Error In Timer

As I wrote before, the actual creation of a timer is not challenging. I am having an issue, however, on stopping the timer. I have inserted the correct stop codes, but obviously something is wrong. Whenever someone succeeds at finding the object and proceeding to the next screen, the timer continues to run (though I cannot see it), eventually forcing my player to fail at the game. For now, I have changed my timer to read 100 seconds so that the player doesn't fail even if they win. I will update if I ever get it fixed.