You don't say what operating system you are using -- but Macs have a problem showing some file formats.
Also, do you have the latest version of Quicktime Player?
And have you started a project yet for this video in Premiere Elements? You need to start a project in order for the program to install some important components for reading the files.
I use windows 8, and i have started a project and installed the latest version of Quicktime. I also installed software wich came with the Sony camera called PMB. I was hoping this program will install the right codec.
I have read somewhere on the adobe forum that some codecs need to be activated, but i hav never found out where to do that. TerjeP
The codecs are activated when you start a new project and add video from that camcorder to your timeline.
If doing that doesn't show your thumbnails, it could well be a Windows 8 issue. Windows 8 is still a relatively new operating system, and may not be completely patched until SP1. However, manually going to Windows Update and making sure you have the non-critical updates (which don't install automatically) and the latest driver for your video card from the ATI or nVidia site may well help.
I uninstalled elements and premier. And set the files mts and m2ts back to start with default win 8 Video player.
Then I installed elements again and choose update thumbnails in the organizer, and i worked perfect.
Finaly I installed premiere again and now everything is workin perfect.
Glad that you have gotten what you need, and thank you for reporting your solution to the problem. That will probably help others in the future.