When I log into any of my email accounts on roundcube mail it brings me back to the login screen with no error message after I click login but if I refresh the page it will sometimes go to the inbox. Also while playing around with mail the session will unexpectedly end and give no error message on the login screen.
PS: This ususally happens after I have logged in and logged out before.
you can test it on my server at:
Also when I clear cookies everything works fine for about a minute.