I've been trying to purchase a license for the new version of thrupaint for SU 2026 V28d and getting a notice saying sorry were having temporary difficulties." - any advice please -- thank you, Billy

I've been trying to purchase a license for the new version of thrupaint for SU 2026 V28d and getting a notice saying sorry were having temporary difficulties." - any advice please -- thank you, Billy

Im new to this site.
Once I download a plugin to my desktop - it appears to be saved as SU file.
How do I get it into my SU 2017 windows?
thanks,
Billy