This message is rare, and appears to indicate that the IIS process on the server may have become "confused" or corrupted in some way. It is typically fixed by simply restarting IIS on the server where PanatrackerGP is hosted.
1. From the Start menu, click Run.
2. In the Open box, type cmd, and click OK.
3. At the command prompt, type iisreset /stop. IIS will attempt to stop all services and will return confirmation once all services have been stopped.
4. At the command prompt, type iisreset /start.
5. That’s it, IIS has been restarted.