Occasionally tasks can take time to run, especially when you are working on large files, or over several repeats.
The inconspicuous Activity Window enables you to cancel tasks which are taking a long time - useful if you did not actually mean to do them! For example, if you accidentally click on the background of a design with the the Magic Wand Tool.
Open ‘Activity’ from the Window Menu. The active task will be listed. Simply press the Cancel button to stop it.