Topaz Gigapixel 8.11 Not Working

I have just installed 8.11 and it simply hangs saying “processing”. I skipped Ver 7 because I was not happy with it. How can I get hold of a copy of my original Ver 6 which worked well?

Hi.

Gigapixel 6.3.3 link for both Windows and Mac

Windows
https://downloads.topazlabs.com/deploy/TopazGigapixelAI/6.3.3/TopazGigapixelAI-6.3.3-windows-x64-Full-Installer.exe

Mac
https://downloads.topazlabs.com/deploy/TopazGigapixelAI/6.3.3/TopazGigapixelAI-6.3.3-osx-Full-Installer.dmg

And the link for previous versions