Similar to EMBJOPR-236, if not the same.

STR (or, better said, happened after this was done):

1) Install and run EAP 5.1.0.CR3.5 -c default
2) Deploy some EJB3 (attached)
3) Run it's Stop operation
4) Run it's Restart operation
5) That caused the attached exception to be thrown.

Or simply Stop and Start several times, it happens quite often.
Sometimes an exception page is shown, sometimes it's only visible in logs.
I haven't noticed this before, so I'd say it's a regression.