Hi
I just tried to enter a resource that does not exist using NAV 2018 last update, error message is different:

You may need to debug or ask your partner to debug that
As a test, if you select another resource name, does it work? Or is it same issue with all resources?
If all resources are failing, then... maybe permission access but I would expect a different error message.
Is it first time user tries to use a resource?
Jerome