I have searched here and found some webmaster also have the same problem. Users can login sometimes but most of the time recieve the:
Sorry, only members with sufficient permission can access this page.
A security error has occurred with authentication.
Please ensure that all cookies are enabled on your web browser, and you are not using a saved or cached copy of the page.
I've tried somethings to fix this - i removed the captcha from the login/register and renamed the default cookie name. But this doesn't seem to help - i am lost to what i should try next - do i install 8.0 beta 2?
Any ideas of what might be causing this problem?
Regards,
Elmar