This is a recurring problem with updates in the creative cloud. I think it is something to do with the fact that .mts files are designed to have a whole bunch of files associated with them... and we all just strip that garbage away and drag the .mts into the comp!
Anyway... whatever reason... it is monumentally simple to fix.
FIRST - This is a vital step!! - Rename the folder with your .mts files (project will need to be shut).
SECOND - open the comp and right click on the .mts file in the project tab and click the "link media..." . Then press the locate button. direct it to the file. This should automatically find all of them, but if it doesn't, highlight the files you are having trouble with and link them as well.
If you skip step one, it will say .mts files are an unsupported format. No idea why it does this, but either way, this fixes it.
that is all.
