Toolpath modification dangers due to bug

[instcell13]

I recently discovered a small bug that has the potential for extreme danger. 

In the most recent build of Fusion 360 if you copy a toolpath that has modifications to another setup, even duplicated and identical, it will silently strip the toolpath modifications off and not warn you.

This caused a large crash because a known proven program was copied and changed to a different WCS, Fusion silently removed the toolpath modification allowing an errant path, and neither Fusion simulation nor the machines own simulation caught it.

Attached is a video of the behavior. I have been able to repeat this on several different files and with different toolpaths (parallel, trace, 2d contour, and others.)

Also attached is an image of the toolpath that caused the crash. For unknown reasons the parallel pass is generating cut lines on geometry that does not exist in an area it knows it cant reach. This is an issue we have been having in the most recent updates but not as alarming an issue as the silent toolpath modification removal bug.

To anyone who sees this, be careful with toolpath modifications and always double and triple check that they are still there. Or ideally do not use them to remove crash-causing tool movements as the software seems to occasionally ignore such modifications.

To autodesk, please fix this issue. I will cooperate and provide any information I can if needed.

[seth.madore]

While this was an intentional change we implemented several years ago, we have since reassessed that approach and logged an improvement task to revert those changes. We have this logged as CAM-60618 and I've added your voice to this ticket.

[Jeff_L]

I just encountered this bug as well. The modifications still aren't preserved even if the toolpaths are protected.