You have to understand that alarms are not necessarily a complete diagnostic of the problem, but might be the end result of a chain of events.
As PBMW tried to inform you, the fact that the turret is not in position is what is preventing it from moving into final engagement of the coupling, and all the controller knows is that no feedback was received from any switch indicating that the turret had settled into its clamped position.
IOW, there is no 'turret lock', in a literal sense, because it is a condition of the turret and not a device in the turret.
First you get good, then you get fast. Then grouchiness sets in.
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)