I have scoured the forums and attempted all of the things people have said (except for re-installing my OS) and can't find the solution to this nightmare.
Our school has Inventor 2012. It installed fine, but when we open it it says the trial version will be expiring. I have the activation code. When I activate online it says it is activated until the next restart of the program. When I manually activate it gives an error and kicks me back to the activation code screen.
Like I said, activating online works fine until the program is closed and re-started.
When you restart Inventor it should automatically re-register / prompt for activation and as a result a new adskflex_*_tsf.data file will be created, potentially resolving this activation loop.
If you receive an activation limit reached error, please either send me a Private Message (click on my philip.s profile name and then "Send this user a private message") with the serial number + request code, or contact our License Assistance team for additional assistance.