Q: After logging in via Gnatsweb, the main screen is displayed, but whatever action is selected (whatever button is clicked), the login screen gets displayed again.
A: This is usually a problem of cookies getting ignored. Gnatsweb uses cookies to store the login information (see "Gnatsweb and Cookies" below). Configure your web browser to allow the cookies Gnatsweb tries to set.
Q: There is not even the main screen, the user immediately gets the login screen when trying to log in. The login data entered is correct. It works fine on another machine and for other users.
A: This has actually been reported only once; but as the effect is similar to the previous one, it is included in the FAQ. It apparently was related to very strict security settings, but has not been investigated in detail.