What operating system are you using?
The Mac version sometimes will not show thumbnails for certain file formats.
If you are using the Windows version, have you ensure you have the latest version of Quicktime installed?
In either event, have you started a new project with this video as the first clip on the project timeline? The Elements bundle will not download many components until it needs them in a Premiere Elements project.
Steve - thanks for the suggestions.
I'm using Windows 7. I've checked and do have the latest version of Quicktime.
In fact I haven't yest created the project for the video files that I've downloaded. I simply selected Organizer (not Premiere Elements) from the welcome screen, created a new catalogue and some albums and downloaded into them.
I've subsequently found some other threads on this subject and gather that, for whatever reason, there are often files for which thumbnails are never proiduced. I guess I'll have to live with it - although it's somewhat irritating!
As I said, starting a new project and adding one of those files to your timeline will often cause the program to download the necessary components and make your file visible in the Organizer.
It doesn't always work. But it should work for virtually all major camcorder formats.
I don't know if you were able to sort this out but what you need is the appropriate Codec installed. If you are using Windows 7, scour the WEB for the Windows 7 Codec pack. This will install the appropriate MTS extension codecs you require. I had the same issues.
This is the one I used: http://download.cnet.com/Windows-7-Codec-Pack/3000-13632_4-10965840.html
This should do the trick. Lyndon
PS. You will have to 'update thumbnails' once in Organiser and the Codec App has run [and PC subsequently restarted].