xWiki LTS Upgrade 12.10.10 -> 13.10.3 HTTP 500 Error and NullPointerException

Help / Discuss
#1

We are running xWiki on LTS-version 12.10.10. The following updates ara available:

xwiki-common/lts 13.10.3 all [upgradable from: 12.10.10]
xwiki-mysql-common/lts 13.10.3 all [upgradable from: 12.10.10]
xwiki-tomcat8-common/lts 13.10.3 all [upgradable from: 12.10.10]
xwiki-tomcat8-mysql/lts 13.10.3 all [upgradable from: 12.10.10]

Installing those updates works just fine. But when I try accessing the wiki, I get a HTTP 500 Error and a NullPointerException from java.

HTTP Status 500 – Internal Server Error

Type Exception Report

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

java.lang.NullPointerException
	com.xpn.xwiki.web.Utils.getContextComponentManager(Utils.java:690)
	com.xpn.xwiki.web.Utils.getComponent(Utils.java:747)
	com.xpn.xwiki.web.Utils.getComponent(Utils.java:776)
	com.xpn.xwiki.web.Utils.getComponent(Utils.java:729)
	org.xwiki.wysiwyg.filter.ConversionFilter.doFilter(ConversionFilter.java:55)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	org.xwiki.container.servlet.filters.internal.SetHTTPHeaderFilter.doFilter(SetHTTPHeaderFilter.java:63)
	org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:208)
	org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:111)
	org.xwiki.resource.servlet.RoutingFilter.doFilter(RoutingFilter.java:132)

Note The full stack trace of the root cause is available in the server logs.
Apache Tomcat/8.5.39 (Ubuntu)

I already had the same problem when trying to update to 13.10.2, but I waited until 13.10.3 to ask here.
Do any of you have an idea why this is happening?

#2

This error does not really give any information (it’s just a consequence of a not fully initialized XWiki). You should take a look at the very first error in the application server log.

#3

Okay, thank you for this info. This helped me solve the issue.
I checked the log before, but now I found a message that /var/lib/xwiki/data/store/solr could not be deleted.
And because I also have problems with SOLR (to be discussed in another forum post), I went ahead and deleted that folder manually.
This made the error go away and I am now able to start the wiki again.