The last assembly does not work

The blacklisting which is mentioned is related to: OSGiEventManager should do safe method calls and identify handlers that are blocking · Issue #4591 · eclipse-archived/smarthome · GitHub

And that timeout can / will brick your karaf, however I do not see consistent reports abouit, although some references in:

A PR has just been created: Unblock event dispatcher by sjsf · Pull Request #4602 · eclipse-archived/smarthome · GitHub