I've just upgrade d to JIRA v7.4.0
When I Browse Projects, all my projects are listed.
When I select (click on) any of the projects I get the error listed in the title.
I saw a thread suggesting safe mode might the be the way do diagnose the faulty add-on.
Even in safe mode the symptoms are the same.
java.lang.RuntimeException: com.atlassian.cache.CacheException: com.atlassian.util.concurrent.LazyReference$InitializationException: java.lang.IllegalStateException: Invalid BundleContext.