1) Update flash player on your machine from http://www.adobe.com/support/flashplayer/downloads.html
2) If problem still remains - The problem you are facing is probably because of corrupted swf files in your machine. But before advising for reinstallation, can you please share your Operating system information and also if you can see the following folders and files in your machine:
Win: C:\ProgramData\Adobe\Photoshop Elements\10.0\Locale\en_us\Workflow Panels\Create\CreateAir.swf
Mac: /Application Support/Adobe/Photoshop Elements/11.0/Locale/en_us/Workflow Panels/Create/CreateAir.swf
If not then these must have got deleted accidently. In this case you need to reinstall the application.
Related threads for similar issue are here:
Hope it helps