[j_cso]

Looks to me like it actually returns 1 on success, not 0.

https://robodk.com/doc/en/PythonAPI/robo...MoveL_Test
"Returns: returns 0 if the movement is free of collision or any other issues."

[Albert]

The documentation should be correct. The MoveL_Test function should return 0 if everything succeeded. However, you should obtain a negative value if there are path issues (the target is not reachable or the path is not feasible). If you obtain a positive value it means there is a collision.

Can you make sure your robot is not in a collision state while doing the desired movement? According to this function there is a collision with your example.