I have just installed Premiere Elements 12 (without the Photoshop Elements trial option) on Windows 7 system. I have imported into Organizer many AVCHD files already on the hard drive. No thumbnails show up. When I try to play the files from within Organizer I get the following message and Organizer stops.
Do you have the latest version of Quicktime installed on your computer, per the program's requirements?
What format are the AVCHD files? (Premiere Elements prefer .mts or .m2t files -- the format that is formed when you use the Premiere Elements Video Importer tool to get the video from the camcorder to the recorder.)
What model of camcorder is your video coming from?