Question:
Do you get the alarm when the turret unlocks and tries to move?
Does the turret move at all?
If it only moves forward and does not try to rotate it could be that it is not fully unlocking. However, that should also give you a servo overload alarm but if the error too large alarm pops up too quickly it gets there before the time out on the overload.
Have you started digging under the covers? I had this alarm several years ago after a turret crash while toolchanging and I can type up a description of watching the tech fix it; at least as much as I could see.
An open mind is a virtue...so long as all the common sense has not leaked out.