Here are some steps to consider when troubleshooting this issue:

1. Check the permissions of the web service and ensure the user is properly authenticated to access it.
2. Test the user with different browsers to eliminate a caching or configuration issue.
3. Reset the user password to verify if it was due to an expired password issue.
4. Verify that the user is allowed to logon from the workstation you are using.
5. Review the Windows event logs to see if there are system errors affecting the issue.