The best “fix” for any PrimoCache key problem is to contact official support:

Two clicks and a license request later, a small, elegant window asked for a key. The trial had been generous but nagging; the software liked to remind you it was on borrowed time. Marek found a string posted in an obscure pastebin thread labeled “primocache key fixed” and, with a shrug that carried the gravity of someone who’d fixed hardware with bubblegum and prayer, he pasted it in.

If you're looking for:

Once you have the , keep it that way:

When the "Key Fixed" issue occurs, users may experience one or more of the following symptoms: