Are you using the , Ubisoft Connect , or a physical retail version of the game?

Alternatively, community members on the Steam Community have developed an open-source unlocker that automates this fix. 2. Official SecuROM Manual Activation

If you have a retail key but the automatic internet activation fails, you can try Ubisoft's manual unlock page: Visit the Ubisoft - SecuROM Support page.

Create new DWORD (32-bit) values named PartnerKey1 and PartnerKey2 , and set their data to 1 .

If the game launches but bonus missions are locked, you can manually trigger them in the Windows Registry: