Motion error

Running a virtual robot - simulating loading a 5 x 23 pallet- part of it points are on a wrist singularity so used SingArea\LockAxis4  - robot seems to run fine but get a 50080 Position not compatible [nn] for each point affected
Gripper perpendicular to null toolframe so simulated a 5degree 'tilt' - can see wrist jnt 5 well away from singularity but still same error BUT if I remove the SingArea FINE no error! - can someone explain whats going on - can I ignore that error on real robot (dont have yet so cant test)