Suspending a schedule takes quite some time (5-10 seconds). But the user has no indication during that time that the suspending is under way. It seems to the user as if the button does not respond to the click, so the user might click again. Then he will get an error, that the schedule is already suspended. This error, however, does not come as a response to the second click. Instead, seconds after the click, the system errors count at the top right goes up by one, and if you click there, you see the error.