Draftsight Pro 2016/17

I purchased a purpetual licence in Nov 2016 (ref(102110554)) and need to move the software from my original PC to a new Win 10 PC. I have deactivated the original PC and moved the licence back via Internet. I downloaded the latest version (2020) as I can not get hold of the original install files. When I try to activate the program tells me the licence is not valid. Please help.