Help - failure to satisfy velocity initial conditions

After running a number of different simulations in motion successfully, I have suddenly been getting this message:

Failure to satisfy velocity initial conditions.  A probable cause is an over-specification of initial velocities of bodies.  Please specify fewer initial velocities and try again

This occurs even when turning 1 shaft supported by 2 bearings via 1 motor @ 100 rpm and no other inputs. What can cause this?

SolidworksMotion Studies