Runtime Issues

There are also problems that don’t cause compiler errors, and don’t appear to be problems at all at first. Then, they can show up later in development and be very frustrating to track down.

Are You Setting Properties before the Object Is Ready?

This one drives me crazy. Basically, what happens is that you jump to a new frame in the movie or a movie clip, and then try to set or access a property of an object there. However, the frame and its objects haven’t been initialized yet, so the property doesn’t exist.