Cannot install version 2.428?

I have a standard license that entitles me to keep the last version received (but not receive updates anymore).

But when I try to load my license for version 2.428, it shows this error -
"Registration Error
An error has occured while importing the license. If you are sure the license is valid, please contact"

Emailed the above on Friday but no reply yet and I cant use BTT now :frowning:

Anyone has any tips?

im having the same problem as well, except im trying to register a free license that i got from purchasing bettersnaptool