Can't login with Opera

Question

Opera

Linux Opera 11.50, when trying to log in after entering the username and password and pressing the button, writes that "action is not defined." Updating to 11.51 and clearing the cache did not help. On Windows everything is fine.
Has anyone else had this happen with stable versions?

Answer 1

Try this:
F12 -> Check the "Send data about the referring page" checkbox.

Answer 2

Yes, I should have clarified...