Okay so i just found out the problem. One of the scenes in my project; for some reason, all of a sudden messed up.

The other scenes are fine, but the scene (scene 4) will not let me test movie and test scene. It won't even let me export the swf file, it disappears after it's done exporting.

It's been working fine up till now. I have no idea what happened and what to do   ._.