From the Premiere Elements Information FAQ http://forums.adobe.com/thread/1042180
Which version of Quicktime do you have installed?
•You MUST use an account with Administrator Privileges to run Premiere Elements
•(Doing Run as Administrator http://forums.adobe.com/thread/969395 [says Encore and also for "All" versions of Premiere] will sometimes fix "odd" errors)
•What version of Premiere Elements? Include the minor version number (e.g., Premiere Elements 12 with the 12.0.1 update).
•What operating system? This should include specific minor version numbers, like "Mac OSX v10.6.8"---not just "Mac"
•Has this ever worked before? If so, do you recall any changes you made to Premiere Elements, such as adding Plug-ins, brushes, etc.? Did you make any changes to your system, such as updating hardware, printers or drivers; or installing/uninstalling any programs?
•Have you installed any recent program or OS updates? (If not, you should. They fix a lot of problems.)
•What kind(s) of image file(s)? When talking about camera raw files, include the model of camera.
•If you are getting error message(s), what is the full text of the error message(s)?
•What were you doing when the problem occurred?
•What other software are you running?
•Tell us about your computer hardware. How much RAM is installed? How much free space is on your system (C:) drive?
And some other questions...
•What are you editing, and does your video have a red line over it BEFORE you do any work?
What version of Premiere Elements are you using and on what computer operating system is it running?
Are your problems only with QuickTime files with the .mov file extension? What is the video compression used in these files?
What is the brand/model/settings for the camera that is recording the video that you are trying to import in
Do you have any version of QuickTime installed on your computer along with Premiere Elements? In order to use either
QuickTime or Premiere Elements you will be needing administrative computer privileges.
Please go to Publish+Share/Computer/QuickTime and let us know if you have QuickTime presets at that location.
Use the scroll bar to the right of the list of choices under Publish+Share/Computer/ in order to see the
QuickTime choice. Otherwise you will not see QuickTime and think that there are only 3 choices there:
Adobe Flash Video
Finding the presets there will tell us if you have QuickTime installed on your computer at all.
Looking forward to your follow up.