The HVE Driver Model Path Follower option allows for the driver of the vehicle to attempt to follow an indicated path. The control parameters for the driver include an adjustable maximum lateral acceleration value (a.k.a. driver comfort level) that is based on the statistical behaviors of everyday drivers.  The HVE Driver Model is not intended to be used during a crash. When one car crashes into another, the accelerations experienced by the "driver" quickly exceed a normal comfort level (the real driver is probably unconscious anyway), which is why you are getting this error message.  You have two choices to resolve your situation: Either do not use the Path Follower for the collision simulation, or terminate the Path Follower event before the collision. A third option, which is trickier, is to place the final path position at a point that causes the run to terminate just before impact.