Windows 10 update and SmartFTP not supported!

I've been using SmartFTP on windows7 64-bit for some time with no problems. I have been using 6.0.2037.0 for about 2-3 years as it does everything I need and cant justify "buying" it again for more updates.
Yesterday I updated to windows 10 64bit and SmartFTP is not in the application list. If I run directly from the install folder it says SmartFTP is not supported in this version of windows. What gives?
There should be no difference to SmartFTP between windows7 x64 and windows 10 x64.

The latest version is fully compatible with Windows 10. It is available from
Versions that have been released before Windows 10 was available are not compatible.