Registration for notifications on changes does not work

hi there!

We experience the following problem in XWiki 11.10.4 and highly appreciate any hint on where to look first (thx in advance):

I am not able to configure notifications for a normal user in its user profile. I get an error message indicating that it failed to save the changes (not more).

Also:

If I click on the bell in the title bar to configure notifications I get an exception:

image

There is a lengthy trace which does not enlighten me but probably you:

org.xwiki.rendering.macro.MacroExecutionException: Failed to evaluate Velocity Macro for content [#macro (generateNotificationInput $id $reference $label)
  <label class="hidden" for="$id">$services.localization.render($label)</label>##
  <input type="checkbox" id="$id" name="$id" #displayCheckedIfWatched($reference)/>##
#end
{{html clean="false"}} ## we need clean="false" because we want to display the raw content
#if ("$!xcontext.userReference" != '' && $services.notification.isEnabled())
  <li>
    #set ($discard = $xwiki.jsx.use('XWiki.Notifications.Code.Macro.NotificationsMacro'))
    #set ($discard = $xwiki.jsx.use('XWiki.Notifications.Code.NotificationsDisplayerUIX'))
    #set ($discard = $xwiki.ssx.use('XWiki.Notifications.Code.Macro.NotificationsMacro'))
    #set ($discard = $xwiki.ssx.use('XWiki.Notifications.Code.NotificationsDisplayerUIX'))
    ## TODO: replace by $xwiki.sswx.use() or something like this when XWIKI-12788 is closed.
    #set ($discard = $xwiki.linkx.use($services.webjars.url('bootstrap-switch', 'css/bootstrap3/bootstrap-switch.min.css'), {'type': 'text/css', 'rel': 'stylesheet'}))
    <div class="notifications-header">
      <div class="clearfix">
        <div class="col-xs-4">
          <p><strong>$escapetool.xml($services.localization.render('notifications.menu.header'))</strong></p>
        </div>
        <div class="col-xs-8 text-right">
          <p>
            <span class="notifications-header-link">
              <a href="$xwiki.getURL('XWiki.Notifications.Code.NotificationRSSService', 'get', 'outputSyntax=plain')"
                  class="notifications-header-link notifications-rss-link" rel="nofollow external">
                $services.icon.renderHTML('rss')&nbsp;$escapetool.xml($services.localization.render('notifications.rss.feedLink'))
              </a>
            </span>
            <span class="notifications-header-link">
              <a href="$xwiki.getURL($xcontext.userReference, 'view', 'category=notifications')" class="notifications-settings" rel="nofollow">
                $services.icon.renderHTML('cog')&nbsp;$escapetool.xml($services.localization.render('notifications.menu.header.settings'))
              </a>
            </span>
          </p>
        </div>
      </div>
      ##
      ## Display the 3 toggle buttons
      ##
      #if ($services.notification.watch.isEnabled())
        <div class="notifications-toggles clearfix" data-enabled="$services.notification.preferences.hasAnyEnabledNotificationPreferences()">
          #macro(displayCheckedIfWatched $scope)#if($services.notification.watch.isLocationWatched($scope))checked="checked"#end#end
          <pre>
            #generateNotificationInput('notificationPageOnly' $doc.documentReference 'notifications.filters.preferences.label.page')
            #generateNotificationInput('notificationPageAndChildren' $doc.documentReference.lastSpaceReference 'notifications.filters.preferences.label.space')
            #generateNotificationInput('notificationWiki' $doc.documentReference.wikiReference 'notifications.filters.preferences.label.wiki')
          </pre>
        </div>
      #end
      <div class="notifications-header-uix col-xs-12">
      </div>
    </div>
    <div class="notifications-area loading clearfix">
    </div>
  </li>
#end
{{/html}}]
	at org.xwiki.rendering.internal.macro.velocity.VelocityMacro.evaluateString(VelocityMacro.java:139)
	at org.xwiki.rendering.internal.macro.velocity.VelocityMacro.evaluateString(VelocityMacro.java:52)
	at org.xwiki.rendering.macro.script.AbstractScriptMacro.evaluateBlock(AbstractScriptMacro.java:286)
	at org.xwiki.rendering.macro.script.AbstractScriptMacro.execute(AbstractScriptMacro.java:182)
	at org.xwiki.rendering.macro.script.AbstractScriptMacro.execute(AbstractScriptMacro.java:58)
	at org.xwiki.rendering.internal.transformation.macro.MacroTransformation.transform(MacroTransformation.java:297)
	at org.xwiki.rendering.internal.transformation.DefaultRenderingContext.transformInContext(DefaultRenderingContext.java:183)
	at org.xwiki.rendering.internal.transformation.DefaultTransformationManager.performTransformations(DefaultTransformationManager.java:101)
	at org.xwiki.rendering.async.internal.block.AbstractBlockAsyncRenderer.transform(AbstractBlockAsyncRenderer.java:74)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRenderer.tranform(DefaultBlockAsyncRenderer.java:143)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRenderer.execute(DefaultBlockAsyncRenderer.java:126)
	at org.xwiki.rendering.async.internal.block.AbstractBlockAsyncRenderer.render(AbstractBlockAsyncRenderer.java:157)
	at org.xwiki.rendering.async.internal.block.AbstractBlockAsyncRenderer.render(AbstractBlockAsyncRenderer.java:54)
	at org.xwiki.uiextension.internal.WikiUIExtension.render(WikiUIExtension.java:179)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor$DecoratorWrapper.render(DefaultBlockAsyncRendererExecutor.java:67)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor$DecoratorWrapper.render(DefaultBlockAsyncRendererExecutor.java:49)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.lambda$syncRender$0(DefaultAsyncRendererExecutor.java:264)
	at com.xpn.xwiki.internal.security.authorization.DefaultAuthorExecutor.call(DefaultAuthorExecutor.java:98)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.syncRender(DefaultAsyncRendererExecutor.java:264)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.render(DefaultAsyncRendererExecutor.java:229)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor.execute(DefaultBlockAsyncRendererExecutor.java:125)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor.execute(DefaultBlockAsyncRendererExecutor.java:113)
	at org.xwiki.uiextension.internal.AbstractWikiUIExtension.execute(AbstractWikiUIExtension.java:112)
	at sun.reflect.GeneratedMethodAccessor297.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:395)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:384)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:173)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:280)
	at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:567)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:151)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:280)
	at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:567)
	at org.apache.velocity.runtime.parser.node.ASTExpression.value(ASTExpression.java:71)
	at org.apache.velocity.runtime.parser.node.ASTSetDirective.render(ASTSetDirective.java:142)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:87)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.directive.Foreach.render(Foreach.java:420)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:207)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.directive.Block.render(Block.java:82)
	at org.apache.velocity.runtime.directive.Block$Reference.render(Block.java:161)
	at org.apache.velocity.runtime.directive.Block$Reference.toString(Block.java:170)
	at sun.reflect.GeneratedMethodAccessor387.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:395)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:384)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:173)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:280)
	at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:567)
	at org.apache.velocity.runtime.parser.node.ASTExpression.value(ASTExpression.java:71)
	at org.apache.velocity.runtime.parser.node.ASTSetDirective.render(ASTSetDirective.java:142)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:342)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluateInternal(DefaultVelocityEngine.java:259)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:222)
	at com.xpn.xwiki.render.DefaultVelocityManager.evaluate(DefaultVelocityManager.java:358)
	at org.xwiki.rendering.internal.macro.velocity.VelocityMacro.evaluateString(VelocityMacro.java:131)
	at org.xwiki.rendering.internal.macro.velocity.VelocityMacro.evaluateString(VelocityMacro.java:52)
	at org.xwiki.rendering.macro.script.AbstractScriptMacro.evaluateBlock(AbstractScriptMacro.java:286)
	at org.xwiki.rendering.macro.script.AbstractScriptMacro.execute(AbstractScriptMacro.java:182)
	at org.xwiki.rendering.macro.script.AbstractScriptMacro.execute(AbstractScriptMacro.java:58)
	at org.xwiki.rendering.internal.transformation.macro.MacroTransformation.transform(MacroTransformation.java:297)
	at org.xwiki.rendering.internal.transformation.DefaultRenderingContext.transformInContext(DefaultRenderingContext.java:183)
	at org.xwiki.rendering.async.internal.block.AbstractBlockAsyncRenderer.transform(AbstractBlockAsyncRenderer.java:76)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRenderer.tranform(DefaultBlockAsyncRenderer.java:143)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRenderer.execute(DefaultBlockAsyncRenderer.java:126)
	at org.xwiki.rendering.async.internal.block.AbstractBlockAsyncRenderer.render(AbstractBlockAsyncRenderer.java:157)
	at org.xwiki.rendering.async.internal.block.AbstractBlockAsyncRenderer.render(AbstractBlockAsyncRenderer.java:54)
	at org.xwiki.uiextension.internal.WikiUIExtension.render(WikiUIExtension.java:179)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor$DecoratorWrapper.render(DefaultBlockAsyncRendererExecutor.java:67)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor$DecoratorWrapper.render(DefaultBlockAsyncRendererExecutor.java:49)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.lambda$syncRender$0(DefaultAsyncRendererExecutor.java:264)
	at com.xpn.xwiki.internal.security.authorization.DefaultAuthorExecutor.call(DefaultAuthorExecutor.java:98)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.syncRender(DefaultAsyncRendererExecutor.java:264)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.render(DefaultAsyncRendererExecutor.java:247)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor.execute(DefaultBlockAsyncRendererExecutor.java:125)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor.execute(DefaultBlockAsyncRendererExecutor.java:113)
	at org.xwiki.uiextension.internal.AbstractWikiUIExtension.execute(AbstractWikiUIExtension.java:112)
	at sun.reflect.GeneratedMethodAccessor297.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:395)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:384)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:173)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:280)
	at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:567)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:151)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:280)
	at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:369)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:87)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.directive.Foreach.render(Foreach.java:420)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:207)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:216)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:311)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:230)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:207)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:87)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:342)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluateInternal(DefaultVelocityEngine.java:259)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:222)
	at com.xpn.xwiki.render.DefaultVelocityManager.evaluate(DefaultVelocityManager.java:358)
	at com.xpn.xwiki.internal.template.VelocityTemplateEvaluator.evaluateContent(VelocityTemplateEvaluator.java:95)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.evaluateContent(TemplateAsyncRenderer.java:217)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.renderVelocity(TemplateAsyncRenderer.java:180)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.render(TemplateAsyncRenderer.java:137)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.render(TemplateAsyncRenderer.java:53)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.lambda$syncRender$0(DefaultAsyncRendererExecutor.java:264)
	at com.xpn.xwiki.internal.security.authorization.DefaultAuthorExecutor.call(DefaultAuthorExecutor.java:98)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.syncRender(DefaultAsyncRendererExecutor.java:264)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.render(DefaultAsyncRendererExecutor.java:247)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor.render(DefaultBlockAsyncRendererExecutor.java:154)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.render(InternalTemplateManager.java:772)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.renderFromSkin(InternalTemplateManager.java:745)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.renderFromSkin(InternalTemplateManager.java:725)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.render(InternalTemplateManager.java:711)
	at com.xpn.xwiki.internal.template.DefaultTemplateManager.render(DefaultTemplateManager.java:78)
	at com.xpn.xwiki.XWiki.evaluateTemplate(XWiki.java:2490)
	at com.xpn.xwiki.XWiki.parseTemplate(XWiki.java:2468)
	at com.xpn.xwiki.api.XWiki.parseTemplate(XWiki.java:992)
	at sun.reflect.GeneratedMethodAccessor273.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:395)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:384)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:173)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:280)
	at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:369)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:216)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:311)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:230)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:207)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:87)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:342)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluateInternal(DefaultVelocityEngine.java:259)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:222)
	at com.xpn.xwiki.render.DefaultVelocityManager.evaluate(DefaultVelocityManager.java:358)
	at com.xpn.xwiki.internal.template.VelocityTemplateEvaluator.evaluateContent(VelocityTemplateEvaluator.java:95)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.evaluateContent(TemplateAsyncRenderer.java:217)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.renderVelocity(TemplateAsyncRenderer.java:180)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.render(TemplateAsyncRenderer.java:137)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.render(TemplateAsyncRenderer.java:53)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.lambda$syncRender$0(DefaultAsyncRendererExecutor.java:264)
	at com.xpn.xwiki.internal.security.authorization.DefaultAuthorExecutor.call(DefaultAuthorExecutor.java:98)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.syncRender(DefaultAsyncRendererExecutor.java:264)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.render(DefaultAsyncRendererExecutor.java:247)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor.render(DefaultBlockAsyncRendererExecutor.java:154)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.render(InternalTemplateManager.java:772)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.renderFromSkin(InternalTemplateManager.java:745)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.renderFromSkin(InternalTemplateManager.java:725)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.render(InternalTemplateManager.java:711)
	at com.xpn.xwiki.internal.template.DefaultTemplateManager.render(DefaultTemplateManager.java:78)
	at com.xpn.xwiki.XWiki.evaluateTemplate(XWiki.java:2490)
	at com.xpn.xwiki.XWiki.parseTemplate(XWiki.java:2468)
	at com.xpn.xwiki.api.XWiki.parseTemplate(XWiki.java:992)
	at sun.reflect.GeneratedMethodAccessor273.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:395)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:384)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:173)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:280)
	at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:369)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:216)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:311)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:230)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:207)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:342)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:106)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:342)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluateInternal(DefaultVelocityEngine.java:259)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:222)
	at com.xpn.xwiki.render.DefaultVelocityManager.evaluate(DefaultVelocityManager.java:358)
	at com.xpn.xwiki.internal.template.VelocityTemplateEvaluator.evaluateContent(VelocityTemplateEvaluator.java:95)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.evaluateContent(TemplateAsyncRenderer.java:217)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.renderVelocity(TemplateAsyncRenderer.java:180)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.render(TemplateAsyncRenderer.java:137)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.render(TemplateAsyncRenderer.java:53)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.lambda$syncRender$0(DefaultAsyncRendererExecutor.java:264)
	at com.xpn.xwiki.internal.security.authorization.DefaultAuthorExecutor.call(DefaultAuthorExecutor.java:98)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.syncRender(DefaultAsyncRendererExecutor.java:264)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.render(DefaultAsyncRendererExecutor.java:247)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor.render(DefaultBlockAsyncRendererExecutor.java:154)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.render(InternalTemplateManager.java:772)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.renderFromSkin(InternalTemplateManager.java:745)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.renderFromSkin(InternalTemplateManager.java:725)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.render(InternalTemplateManager.java:711)
	at com.xpn.xwiki.internal.template.DefaultTemplateManager.render(DefaultTemplateManager.java:78)
	at com.xpn.xwiki.XWiki.evaluateTemplate(XWiki.java:2490)
	at com.xpn.xwiki.web.Utils.parseTemplate(Utils.java:179)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:516)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:218)
	at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:425)
	at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:228)
	at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
	at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:634)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:112)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.xwiki.wysiwyg.filter.ConversionFilter.doFilter(ConversionFilter.java:109)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.xwiki.container.servlet.filters.internal.SetHTTPHeaderFilter.doFilter(SetHTTPHeaderFilter.java:63)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:208)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:111)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.xwiki.resource.servlet.RoutingFilter.doFilter(RoutingFilter.java:132)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:678)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1598)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Unknown Source)
Caused by: org.xwiki.velocity.XWikiVelocityException: Failed to evaluate content with id [xwiki:XWiki.Notifications.Code.NotificationsDisplayerUIX^XWiki.UIExtensionClass[0]]
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:227)
	at com.xpn.xwiki.render.DefaultVelocityManager.evaluate(DefaultVelocityManager.java:358)
	at org.xwiki.rendering.internal.macro.velocity.VelocityMacro.evaluateString(VelocityMacro.java:131)
	... 244 more
Caused by: org.apache.velocity.exception.MethodInvocationException: Invocation of method 'isLocationWatched' in  class org.xwiki.notifications.filters.watch.script.NotificationWatchScriptService threw exception java.lang.ClassCastException: com.xpn.xwiki.objects.LargeStringProperty cannot be cast to com.xpn.xwiki.objects.ListProperty at 61:xwiki:XWiki.Notifications.Code.NotificationsDisplayerUIX^XWiki.UIExtensionClass[0][line 40, column 72]
	at org.apache.velocity.runtime.parser.node.ASTMethod.handleInvocationException(ASTMethod.java:243)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:187)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:280)
	at org.apache.velocity.runtime.parser.node.ASTReference.evaluate(ASTReference.java:530)
	at org.apache.velocity.runtime.parser.node.ASTExpression.evaluate(ASTExpression.java:62)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:85)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:216)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:311)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:230)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:207)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:216)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:311)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:230)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:207)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:87)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:87)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:342)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluateInternal(DefaultVelocityEngine.java:259)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:222)
	... 246 more
Caused by: java.lang.ClassCastException: com.xpn.xwiki.objects.LargeStringProperty cannot be cast to com.xpn.xwiki.objects.ListProperty
	at com.xpn.xwiki.objects.BaseCollection.getListValue(BaseCollection.java:490)
	at org.xwiki.notifications.filters.watchlistbridge.internal.WatchlistBridgeProvider.getValues(WatchlistBridgeProvider.java:128)
	at org.xwiki.notifications.filters.watchlistbridge.internal.WatchlistBridgeProvider.getFilterPreferences(WatchlistBridgeProvider.java:115)
	at org.xwiki.notifications.filters.internal.DefaultNotificationFilterPreferenceManager.getFilterPreferences(DefaultNotificationFilterPreferenceManager.java:75)
	at org.xwiki.notifications.filters.watch.WatchedLocationReference.isWatched(WatchedLocationReference.java:87)
	at org.xwiki.notifications.filters.watch.script.NotificationWatchScriptService.isLocationWatched(NotificationWatchScriptService.java:108)
	at sun.reflect.GeneratedMethodAccessor724.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:395)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:384)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:173)
	... 267 more

This looks like https://jira.xwiki.org/browse/XWIKI-17996 (fixed in 11.10.11).