I got the Corel Photo Paint X7 (64-bit) will not open error.

Running Windows 8.1. Draw works fine.  PPT was working 2 days ago! Tried uninstalling/reinstalling.  Restored computer to date when I knew it worked, but nothing fixed this error.  Tried the F8 trick, but that didn't work for me. I use PPT nearly everyday for my photography and I'm attending a photo expo this wknd. REALLY need it work again. Please help!