Social login not working

My site uses super socializer for social login (via twitter). this worked but when i added wp user manager, i cannot login via twitter. site automatically logs me out after getting twitter authorisation (“you are now logged out” -very irritating). i see that registrations are done though (new users created). but those new users cannot login!

when i deactivate wp user manager, then it works. i a new to wp-manager. i check settings but cannot see anything wrong. surely i am doing something wrong. what am i doing wrong?

regards