A revoked license is the software’s way of saying the current credentials are no longer valid. If you're a professional who values your data integrity, the safest and most efficient path forward is to support the developers with a legitimate purchase or contact their support team to rectify a genuine billing error.

Scooter Software, the developers of Beyond Compare, generally revoke keys for a few specific reasons:

If a private license key is posted on a "serial key" website, a forum, or a public GitHub repository, it is added to a blacklist. Once the software checks in with the activation server, it identifies the leaked key and disables it.