Hi, welcome to the forum.
The error doesn't sound like a problem with the license or the iLok, but you really should let us know more in detail what is happening. Does the error show when you launch PT? Have you tried pulling all plugins out of the plugin folder to run PT without 3rd party plugins? Installed/updated anything recently?
And you should give us as much info as you can on computer, OS/software versions, etc. Start here:
Help Us Help You
You might create a signature with your system specs in it. Go to the "User CP".