Problem with trial extension on Linux server

Hello,

We have a customer trying to extend their evaluation of our product on their Linux server but unfortunately every time they try they get the error "Error attempting to extend evaluation: (1): Licensing operation failed."

We've tried having them resync the time on their server and restart, but it hasn't worked. The license key they're using was generated the day they tried and should be valid through Jan. 31.

Is there any kind of diagnostic or something we can give them to try and figure out what's going on here?

Thanks,Ian