Problem

Attempts to access the Confluence Administration panel, or any admin functions results in a 500 error.

Also, Confluence may fail to start up with these errors.

The following appears in the atlassian-confluence.log

2016-12-23 23:57:34,993 ERROR [ThreadPoolAsyncTaskExecutor::Thread 29] [license.storage.lib.PluginLicenseStoragePluginInstaller] afterPropertiesSet Failed to install or enable the Plugin License Storage plugin version 2.4.1
java.lang.NoSuchMethodError: com.google.common.collect.MapMaker.expiration(JLjava/util/concurrent/TimeUnit;)Lcom/google/common/collect/MapMaker;
	at com.atlassian.upm.Functions.<clinit>(Functions.java:121)
	at com.atlassian.upm.Functions$CachedFunction2.cache(Functions.java:170)
	at com.atlassian.upm.osgi.impl.Wrapper2.<init>(Wrapper2.java:41)
	at com.atlassian.upm.osgi.impl.Wrapper$1.<init>(Wrapper.java:22)

And:

NoClassDefFoundError: Could not initialize class com.atlassian.upm.osgi.impl.Versions

Environment

• Upgraded to Confluence 6.0 or above

Cause

This is caused by an older Add-Ons using a different version of the Google Guava library than what is used in Confluence. There are several Add-Ons that this error appears with, that include (but not limited to)

• Template Ops by DEISER LABS

• User Profiles for Confluence by Communardo Software GmbH (affecting any version older than 1.11 in Confluence 6.0, bug fixed in 1.11)
• Page View by Andy Ng
• Scroll CHM Exporter by K15t Software GmbH

Resolution 1

If access to admin functions are available then

1. Go to  > Add-ons
2. Update all the Add-Ons with updates
3. Uninstall all the Add-Ons that have errors
4. Shutdown Confluence
5. Delete the all the files and folders in (may need adjusting for your environment), see How to clear Confluence plugins cache for more information.
   • <confluence-home>/bundled-plugins
   • <confluence-home>/plugins-cache
   • <confluence-home>/plugins-osgi-cache
   • <confluence-home>/plugins-temp
   • <confluence-home>/bundled-plugins_language (might not exist)
6. Restart Confluence

Resolution 2

If no admin functions are available, run the following query in the Confluence Database:

select plugindataid, pluginkey, filename, lastmoddate from PLUGINDATA;

You will see an output similar to this (check for the Add-On causing the problem):

8847361 | com.deiser.confluence.template-ops | plugin.8517301421743055915.template-ops-1.1.1.jar | 2016-12-06 14:48:18.498

Take note of the PLUGINDATAID, and use it in the next query (take a DB backup first before running this!):

DELETE FROM PLUGINDATA WHERE PLUGINDATAID = <PLUGINDATAID>;

Replace <PLUGINDATAID> with the PLUGINDATAID from the query output earlier.

Then remove the following from the Confluence Home Directory:

• bundled-plugins
• plugins-cache
• plugins-osgi-cache
• plugins-temp

Restart Confluence