APP-FND-01931 : your session is no longer valid or your logon information could not be reestablished from your session.
Solution:-
1. Open Internet Explorer (version: 9, 10)
2. Tools -> Internet Options -> "Security" tab
3. Select "Custom Level" button
4. Scroll down to the bottom to find "Enable XSS filter" under "Scripting". If it is "Enabled",
change it to "Disable"
5. Click OK, Apply, OK
6. Restart the IE and try to open Oracle Applications forms