System exception.The activity 'Try Catch' with ID 21 threw or propagated an exception while being canceled.?

[donghai (zhaodonghai)]

Hi @rahmachabbeh21
If you used like parallel activity or pickbanch activity, maybe you can follow this thread.

Cancelling browser operation throws an error

I think the problem is related with activities that contain non Thread Safe variables, because this is usually happening while using Parallel or Pick activities and trying to cancel the branch that contains any UiPath activity but especially Ui interacting ones.

BR,