I also just installed JBoss Tolls version 4.4.2.Final form the eclipse marketplace.
You mean 4.2.2.Final, right?
Could you also attach or post full stacktrace for exception? We could try to fix it and put into coming service release.
It is important that you, just like what Denis suggests, attach the stack trace. But it would also be good to attach a minimal project that can be used to reproduce the issue and/or a description of the actions and the conditions that are needed to reproduce it. I have tried to reproduce this with a vanilla JPA 2.1 project without success.