The "Pervasive license key" has expired or you have exceeded your user licenses or Pervasive is installed on more computers than what you have licenses for. Sometimes you have enough licenses but Pervasive is holding onto extra users. 


*Restart the pervasive services on the server to release all users.

If the license key has expired, it means that the customer have been operating on a 10 or 30 days key and will have to get a new one or If the customer have exceeded his license user count, the customer will need to purchase additional users from Pervasive.