[maexbecks]

While creating a gripper mechanism I used the measure tool to measure the TCP on the newly created mechanism. While the measurement was still active I updated the mechanism which crashed RoboDK.

Steps:
- Modify robot on the attached station which simply consists of a Schunk gripper
- Tools -> Measure
- measure any point on the newly created mechanism, not the original model
- do not close the measure window and do not clear the selection
- update mechanism