Error while using the while while using single sign on from SAP logon:
GSS-API(maj) - No valid credentials provided ( or available)
The users Kerberos ticket is only valid for a certain amount of time. If the user never does an new auth before it expires, then they end up with an expired ticket and the message they are seeing. (Windows doesn't care that their ticket is expired because it falls back to NTLM) but SNC does care.
If the user locks their desktop and then unlocks it it forces a new authentication and a renewal of their Kerb tickets. They need to enforce an auth at least once before their tickets are set to expire. Or just remember to always lock your desktop and unlock it when they get this error.
If you install Microsoft’s Kerbtray and look at the Kerberos you will see the details of this issue.