Today I discovered that Flash truly has a limit!
16,000 frames: Exceeding this limit causes the movie playback to stop. While this limit is rarely reached by most developers, it is possible. If your movie must have more than this number of frames,try creating multiple movies with fewer than 16,000 frames each and then linking the movies togetherusing a method such as the ActionScript 2 loadMovie() command.
16,000 layers: Flash is not capable of working with more than 16,000 layers in a movie.
16,000 loaded movies: You cannot load more than 16,000 movies into Flash player.
16,000 symbol instances: Flash does not allow more than 16,000 symbol instances in a Flash movie
2880 x 2880 px canvas size: A Flash movie cannot be larger than 2880 px wide or 2880 px tall.
Take a look at the adobe knowledge base for more information…