I have an MS Exchange 2003 server that I have been running OWA without incident on for quite a while. I just ran into an issue with only one user not being able to login to OWA. The user tries to login using their credentials and they get the following message in IE:
The website declined to show this webpage
Most likely causes:
This website requires you to log in.
I have tested other users that are in the same OU and have the same permissions and they are working fine its just this one user that gets this message.
I have done some searching on this issue but it seems most of the help is targeted at people that have multiple users that cannot login.