Pinnacle 12 working fine on Windows 8 nagging pop ups to upgrade to 8.1 .... Did it and now Pinnacle 12 doesn't launch due to compatibility issue? Does reinstalling pinnacle 12 fix the issue? Anyone can confirm if this version no longer works with 8.1??

I once tried it too and had some issues with all previous versions of Studio. You may want to wait until the full version of Windows 10 is released to see if they have fixed this problem. For the mean time Studio 12 is not compatible with W10.

joetavola:

Pinnacle 12 working fine on Windows 8 nagging pop ups to upgrade to 8.1 .... Did it and now Pinnacle 12 doesn't launch due to compatibility issue? Does reinstalling pinnacle 12 fix the issue? Anyone can confirm if this version no longer works with 8.1??

I stopped @ W7. So don't know how W8.1 handles Installing/Running Programs Developed for previous Windows Versions.

Try Right-Clicking on S12 Desktop Icon / Troubleshoot compatibility, if you haven't already done-so.