I'm afraid I am trouble understanding what you are saying. The one thing I can see is that when you try to select your Usergroup you get a bus error message. This would suggest that the saved information has become corrupted.
Since you have recently acquired the machine, it is hard to know what its condition is. I would suggest that you return the unit to factory defaults as described in the Manual, and then rebuild your maps/groups. It will then be in a known state.