Hi, the old lifetime Premium licenses do not expire.
I'm still using the same license I bought in 2010.
So I think that there's an error in the data you're entering.
You always can ask Sindre to resend your license information, but that requires that you still use the same emailaddress.
But your key is just an MD5 hash of the email you used to register.
So you can check your key on this site:
https://www.md5hashgenerator.com/