If video processing fails to find the feature what it is looking for, it pauses and the software presents you with this dialog:
The background is red to catch your attention. The process behind is just paused; you can tune the algorithm, move the machine and so on, to give the vision process another chance to get things right. Click “Retry” to run the vision process again. Click “Cancel” to let the process fail.
You can move the dialog to a position that gives you access to what ever buttons etc you might need.