WESM Web Authentication Failure for 1 hour !!!

[peter massey]

I have a strange issue on a HP5400 WESM the system has been working fine with no issues for 8 months but from Monday afternoon when an account is configured via the guest account or the superuser account the account is created with all time information shown being correct, however when we try and use the account we get authentication failure this carries on for 1 hour. We have checked the times/dates on the WESM and PC and all are correct. Can anyone help