From your screenshot ( the one you sent by email, which shows your key ), it seems you are trying to activate GSX L2, or maybe another product with a GSX key.
- To activate GSX Level 2, you must select GSX Level 2 in the Addon Manager menu, THEN press the "Register Serial" button, and insert a GSX Level 2 Activation key
- To activate GSX, you must select GSX in the Addon Manager menu, THEN press the "Register Serial" button, and insert a GSX Activation key.
You have been replied by email too.
Please don't post the same question twice. All email are replied to, and posting the same question on the forum and by email, is only making support slower for everybody ( including you ), because it double our support effort, in order to not let anything unanswered. Support questions about orders, like this one, should ALWAYS be made using Email.