Failed to execute the [office] macro. Cause: [null]. Click on this message for details

Xwiki Version: 13.10.2
OS: CentOS7

Installed office server and that is in connected state - Refer the enclosed screenshot.
Office-server-connected

And we’re not getting - how to install Office macro from this link - Office Macro (XWiki.org) . And searched for ‘Office Macro’ on Global Administration → extensions, but not finding. Can you guide us on how to install office macro in a little better way, compared to the above macro link?
And we tried testing it, receiving this error - Failed to execute the [office] macro. Cause: [null]. Click on this message for details.

org.xwiki.rendering.macro.MacroExecutionException: Failed to view office attachment.
	at org.xwiki.rendering.internal.macro.office.OfficeMacro.execute(OfficeMacro.java:114)
	at org.xwiki.rendering.internal.macro.office.OfficeMacro.execute(OfficeMacro.java:55)
	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:88)
	at org.xwiki.display.internal.DocumentContentAsyncExecutor.executeInCurrentExecutionContext(DocumentContentAsyncExecutor.java:348)
	at org.xwiki.display.internal.DocumentContentAsyncExecutor.execute(DocumentContentAsyncExecutor.java:221)
	at org.xwiki.display.internal.DocumentContentAsyncRenderer.execute(DocumentContentAsyncRenderer.java:107)
	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.rendering.async.internal.DefaultAsyncRendererExecutor.syncRender(DefaultAsyncRendererExecutor.java:273)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.render(DefaultAsyncRendererExecutor.java:250)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor.execute(DefaultBlockAsyncRendererExecutor.java:125)
	at org.xwiki.display.internal.DocumentContentDisplayer.display(DocumentContentDisplayer.java:67)
	at org.xwiki.display.internal.DocumentContentDisplayer.display(DocumentContentDisplayer.java:43)
	at org.xwiki.display.internal.DefaultDocumentDisplayer.display(DefaultDocumentDisplayer.java:96)
	at org.xwiki.display.internal.DefaultDocumentDisplayer.display(DefaultDocumentDisplayer.java:39)
	at org.xwiki.sheet.internal.SheetDocumentDisplayer.display(SheetDocumentDisplayer.java:123)
	at org.xwiki.sheet.internal.SheetDocumentDisplayer.display(SheetDocumentDisplayer.java:52)
	at org.xwiki.display.internal.ConfiguredDocumentDisplayer.display(ConfiguredDocumentDisplayer.java:68)
	at org.xwiki.display.internal.ConfiguredDocumentDisplayer.display(ConfiguredDocumentDisplayer.java:42)
	at com.xpn.xwiki.doc.XWikiDocument.display(XWikiDocument.java:1228)
	at com.xpn.xwiki.doc.XWikiDocument.getRenderedContent(XWikiDocument.java:1365)
	at com.xpn.xwiki.doc.XWikiDocument.displayDocument(XWikiDocument.java:1314)
	at com.xpn.xwiki.doc.XWikiDocument.displayDocument(XWikiDocument.java:1283)
	at com.xpn.xwiki.api.Document.displayDocument(Document.java:794)
	at jdk.internal.reflect.GeneratedMethodAccessor283.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:571)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:554)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:221)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:368)
	at org.apache.velocity.runtime.parser.node.ASTReference.value(ASTReference.java:704)
	at org.apache.velocity.runtime.parser.node.ASTExpression.value(ASTExpression.java:75)
	at org.apache.velocity.runtime.parser.node.ASTSetDirective.render(ASTSetDirective.java:242)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:147)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:439)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:190)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:147)
	at org.xwiki.velocity.internal.directive.TryCatchDirective.render(TryCatchDirective.java:86)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:304)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:439)
	at org.apache.velocity.Template.merge(Template.java:358)
	at org.apache.velocity.Template.merge(Template.java:262)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:280)
	at com.xpn.xwiki.render.DefaultVelocityManager.evaluate(DefaultVelocityManager.java:321)
	at com.xpn.xwiki.internal.template.VelocityTemplateEvaluator.evaluateContent(VelocityTemplateEvaluator.java:95)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.evaluateContent(TemplateAsyncRenderer.java:225)
	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$0(DefaultAsyncRendererExecutor.java:267)
	at com.xpn.xwiki.internal.security.authorization.DefaultAuthorExecutor.call(DefaultAuthorExecutor.java:98)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.syncRender(DefaultAsyncRendererExecutor.java:267)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.render(DefaultAsyncRendererExecutor.java:250)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor.render(DefaultBlockAsyncRendererExecutor.java:154)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.render(InternalTemplateManager.java:772)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.renderFromSkin(InternalTemplateManager.java:745)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.renderFromSkin(InternalTemplateManager.java:725)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.render(InternalTemplateManager.java:711)
	at com.xpn.xwiki.internal.template.DefaultTemplateManager.render(DefaultTemplateManager.java:78)
	at com.xpn.xwiki.XWiki.evaluateTemplate(XWiki.java:2509)
	at com.xpn.xwiki.XWiki.parseTemplate(XWiki.java:2487)
	at com.xpn.xwiki.api.XWiki.parseTemplate(XWiki.java:997)
	at jdk.internal.reflect.GeneratedMethodAccessor222.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:571)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:554)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:221)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:368)
	at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:492)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:147)
	at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:218)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:331)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:261)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:304)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:439)
	at org.apache.velocity.Template.merge(Template.java:358)
	at org.apache.velocity.Template.merge(Template.java:262)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:280)
	at com.xpn.xwiki.render.DefaultVelocityManager.evaluate(DefaultVelocityManager.java:321)
	at com.xpn.xwiki.internal.template.VelocityTemplateEvaluator.evaluateContent(VelocityTemplateEvaluator.java:95)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.evaluateContent(TemplateAsyncRenderer.java:225)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.renderVelocity(TemplateAsyncRenderer.java:180)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.render(TemplateAsyncRenderer.java:137)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.render(TemplateAsyncRenderer.java:53)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.lambda$syncRender$0(DefaultAsyncRendererExecutor.java:267)
	at com.xpn.xwiki.internal.security.authorization.DefaultAuthorExecutor.call(DefaultAuthorExecutor.java:98)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.syncRender(DefaultAsyncRendererExecutor.java:267)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.render(DefaultAsyncRendererExecutor.java:250)
	at org.xwiki.rendering.async.internal.block.DefaultBlockAsyncRendererExecutor.render(DefaultBlockAsyncRendererExecutor.java:154)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.render(InternalTemplateManager.java:772)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.renderFromSkin(InternalTemplateManager.java:745)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.renderFromSkin(InternalTemplateManager.java:725)
	at com.xpn.xwiki.internal.template.InternalTemplateManager.render(InternalTemplateManager.java:711)
	at com.xpn.xwiki.internal.template.DefaultTemplateManager.render(DefaultTemplateManager.java:78)
	at com.xpn.xwiki.XWiki.evaluateTemplate(XWiki.java:2509)
	at com.xpn.xwiki.XWiki.parseTemplate(XWiki.java:2487)
	at com.xpn.xwiki.api.XWiki.parseTemplate(XWiki.java:997)
	at jdk.internal.reflect.GeneratedMethodAccessor222.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.doInvoke(UberspectImpl.java:571)
	at org.apache.velocity.util.introspection.UberspectImpl$VelMethodImpl.invoke(UberspectImpl.java:554)
	at org.apache.velocity.runtime.parser.node.ASTMethod.execute(ASTMethod.java:221)
	at org.apache.velocity.runtime.parser.node.ASTReference.execute(ASTReference.java:368)
	at org.apache.velocity.runtime.parser.node.ASTReference.render(ASTReference.java:492)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:147)
	at org.apache.velocity.runtime.directive.VelocimacroProxy.render(VelocimacroProxy.java:218)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:331)
	at org.apache.velocity.runtime.directive.RuntimeMacro.render(RuntimeMacro.java:261)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:304)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:147)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:171)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:147)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:439)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:190)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:439)
	at org.apache.velocity.Template.merge(Template.java:358)
	at org.apache.velocity.Template.merge(Template.java:262)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:280)
	at com.xpn.xwiki.render.DefaultVelocityManager.evaluate(DefaultVelocityManager.java:321)
	at com.xpn.xwiki.internal.template.VelocityTemplateEvaluator.evaluateContent(VelocityTemplateEvaluator.java:95)
	at com.xpn.xwiki.internal.template.TemplateAsyncRenderer.evaluateContent(TemplateAsyncRenderer.java:225)
	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:267)
	at com.xpn.xwiki.internal.security.authorization.DefaultAuthorExecutor.call(DefaultAuthorExecutor.java:98)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.syncRender(DefaultAsyncRendererExecutor.java:267)
	at org.xwiki.rendering.async.internal.DefaultAsyncRendererExecutor.render(DefaultAsyncRendererExecutor.java:250)
	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:2509)
	at com.xpn.xwiki.web.Utils.parseTemplate(Utils.java:179)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:606)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:289)
	at com.xpn.xwiki.web.LegacyActionServlet.service(LegacyActionServlet.java:115)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:764)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:122)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.xwiki.wysiwyg.filter.ConversionFilter.doFilter(ConversionFilter.java:61)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.xwiki.container.servlet.filters.internal.SetHTTPHeaderFilter.doFilter(SetHTTPHeaderFilter.java:63)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:208)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:111)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.xwiki.resource.servlet.RoutingFilter.doFilter(RoutingFilter.java:132)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:540)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
	at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:687)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
	at org.apache.catalina.valves.RemoteIpValve.invoke(RemoteIpValve.java:769)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:357)
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:382)
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:895)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1722)
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: org.xwiki.officeimporter.OfficeImporterException: Error while converting document [test.xlsx] into html.
	at org.xwiki.officeimporter.internal.builder.DefaultXHTMLOfficeDocumentBuilder.build(DefaultXHTMLOfficeDocumentBuilder.java:107)
	at org.xwiki.officeimporter.internal.builder.DefaultXDOMOfficeDocumentBuilder.build(DefaultXDOMOfficeDocumentBuilder.java:85)
	at org.xwiki.office.viewer.internal.DefaultOfficeResourceViewer.createXDOM(DefaultOfficeResourceViewer.java:296)
	at org.xwiki.office.viewer.internal.DefaultOfficeResourceViewer.createXDOM(DefaultOfficeResourceViewer.java:268)
	at org.xwiki.office.viewer.internal.DefaultOfficeResourceViewer.getView(DefaultOfficeResourceViewer.java:362)
	at org.xwiki.office.viewer.internal.DefaultOfficeResourceViewer.createView(DefaultOfficeResourceViewer.java:416)
	at org.xwiki.rendering.internal.macro.office.OfficeMacro.execute(OfficeMacro.java:112)
	... 185 more
Caused by: org.xwiki.officeimporter.converter.OfficeConverterException: Error while performing conversion.
	at org.xwiki.officeimporter.internal.converter.DefaultOfficeConverter.convertDocument(DefaultOfficeConverter.java:110)
	at org.xwiki.officeimporter.internal.converter.DefaultOfficeConverter.convertDocument(DefaultOfficeConverter.java:43)
	at org.xwiki.officeimporter.internal.builder.DefaultXHTMLOfficeDocumentBuilder.build(DefaultXHTMLOfficeDocumentBuilder.java:104)
	... 191 more
Caused by: org.jodconverter.core.office.OfficeException: Task did not complete within timeout: LocalConversionTask{source=SourceDocumentSpecsFromFile{file=test.xlsx, format=xlsx}, loadProperties=null, target=TargetDocumentSpecsFromFile{file=test.html, format=html}, storeProperties=null}
	at org.jodconverter.core.office.AbstractOfficeManagerPoolEntry.execute(AbstractOfficeManagerPoolEntry.java:118)
	at org.jodconverter.core.office.AbstractOfficeManagerPool.execute(AbstractOfficeManagerPool.java:217)
	at org.jodconverter.local.LocalConverter$LocalConversionJob.doExecute(LocalConverter.java:149)
	at org.jodconverter.core.job.AbstractConversionJob.execute(AbstractConversionJob.java:62)
	at org.xwiki.officeimporter.internal.converter.DefaultOfficeConverter.convertDocument(DefaultOfficeConverter.java:106)
	... 193 more
Caused by: java.util.concurrent.TimeoutException
	at java.base/java.util.concurrent.FutureTask.get(FutureTask.java:204)
	at org.jodconverter.core.office.AbstractOfficeManagerPoolEntry.execute(AbstractOfficeManagerPoolEntry.java:88)
	... 197 more

Looks like the LibreOffice server you are using did not answer fast enough for jodconverter taste. Maybe a more recent version would be faster, or you can try to increase the timeout with the openoffice.taskExecutionTimeout property (see Office Importer Application (XWiki.org)).

There are several reasons why this can happen. There’s more info on https://extensions.xwiki.org/xwiki/bin/view/Extension/Office%20Importer%20Application (in the installation section) but ATM xwiki.org seems to be in a bad shape. However it should be back soon though.

Also check your xwiki logs for any more details.