Serial number is not valid - Acrobat X Standard

Good morning,

Just upgraded my PC and tried to move my Acrobat X Standard license over - unfortunately it says "This serial number is not valid for this product" even though the product was installed from the same installer file as the original PC.

I assume this is a "Sorry we don't support Acrobat X any more and aren't even going to try to help you", but want to see if there is something I can do to transfer over the license file (e.g. copy registry entries from the , set up my own authentication server).

Failing that does anybody have any recommendations for PDF editors that don't cost more than my Disney Plus subscription? I don't use it enough to justify this expense - I'm just more annoyed that Adobe would shut down its authentication servers and not release a patch to the software that auto approves the license key.