This can be caused by a variety of reasons. The most frequent cause is tampering with GameShield license files. If you are not yet a client, or you have not yet received your permanent Activation Code, all you need to do is click OK to "recover your software now", then send the Authorization Request Code that appears to our support department and we will send you back a "Recovery Code".
If you are already a client and you have received your permanent Activation Code, you can simply use this dual purpose code to recover your license.