The queue could not be deleted. Possible reasons: 1. There could be other management pack groups or queues referring to this ...

The queue could not be deleted. Possible reasons:

1. There could be other management pack groups or queues referring to this queue. Remove those references before trying to delete this queue.

2. This management pack was modified by another user. Restart the console to apply any changes made to management packs outside of this console session.