I had 3.6 with no issues at all with several cars licensed etc. I just received a tune that was done in 4.0 so to see it and upload it I updated to 4.0. I can view the new file along with my older 3.6 files but now it won't let me upload any of them to vehicles..... cuz as soon as i hit the "write" button it pops up with an "Unhandled exception error" and doesn't let me upload the file.....I also get the same error now when I look under my License info and click the big blue "I" and it says I have no cars licensed....
I hope someone can help asap.