The server you are trying to access is either busy or experiencing difficulties. Please close the Web browser, open a new browser window, and try logging in again
Solution
This issue is mainly due to Siebel application server is down. But I have noticed that this error can be seen due to following reason
1. Multiple session opened in a single browser
If you opened multiple session in single browser, Sibel sometimes shows this message. Even though you don't have another tab opened, this error can be shown. That means there is an open session in cookies. Clear your browser cache is the solution