Bug Report(build 2773) Can't Delete a Group

I removed some fixtures from a group, not realizing they were the only fixtures in that group. This left the group empty. Now I can't delete the group. When I try to delete, merge, or replace the group, I get this message...

Server Busy, Please try again
(object 56 in array 26)

This happens even after rebooting the system. I can move the group, which is what I did for now.
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