Login Not possible

Hi,

Whenever user try to login on portal he gets message

SSO Login not possible: Browsers - sign will not be accepted

FAQ's for the same suggesting that this problem is occured because another session is not proberly logged off.Solution given for the same is to close all the browser ans ohter SAP applications and wait for some time.This will delete all session cookies and then again login will be possible.

We tried the above solution but not working OK.Pl suggest if other solution does exist.

Thanks in advance