IsoDraw CAD Process Loosing License

Hi All

I have one user out of6 with IsoDraw + CaD Process 7.1 m050 who keeps getting a lost license error.

We're running a license server for all PTC licenses and don't see errors with anyone else so I think its something with his install or PC

Have checked the log files and Windows event manager, tested his network connection and see no errors

Its a Windows 7 32bit machine

Has anyone else seen this and can maybe give me a few pointers