If you are involved in 2d animation and you try to import swf files into After Effects CS6, you may encounter weird issues.
These issues usually appear, when you update the swf file while After Effects CS6 is still open. This may turn the swf into a blank or a half time-trimmed clip making your workflow really frustrating. To get around the problem, you should go to After Effects menu Edit>Preferences>Media & Disk Cache and make sure to uncheck the “Write XMP IDs to Files on Import”.
Voila! The problem is resolved :)