If we have a plugin using the lucene-sort-mapper, when switching nodes we get the following exception:

java.lang.IllegalStateException: Cannot retrieve plugin module before it is enabled: PluginModuleHolder[(unknown; not enabled)]
at com.atlassian.confluence.plugin.module.PluginModuleHolder.getModule(PluginModuleHolder.java:102)
	at com.atlassian.confluence.plugin.descriptor.search.AbstractLuceneMapperModuleDescriptor.getModule(AbstractLuceneMapperModuleDescriptor.java:58)

Workaround

The workaround is enabling and disabling the plugin in the other node which fixes it until the next use of the lucene-sort-mapper which will break it again.

I've create a simple component that fires the PluginEnabledEvent which makes it work, but this should be fixed on Atlassian's side.

Please find attached the full stacktrace plus the test component that I used to fix it.

We've disabled this feature and will be waiting for a fix from Atlassian to re-enable it.