I installed Codoforum on my own local server, to test out before posting online. When I try and login, nothing happens. I have tried correct details as well as incorrect details. Nothing happens, not even this user doesn't exist message or password is incorrect. At the bottom of every page there is this:

Warning: session_write_close(): Session callback expects true/false return value in Unknown on line 0

I am not sure how to fix this or if this is effecting the page. This is being run on ubuntu, with php 7.