Well I will upload a slightly modified version of Mys v1.3.0 with new cookies system a few mins later. This should not only resolve your problem with user login, but also improve security significantly.

Edit: Download links updated already, enjoy and please lemme know if it works out for you or not.

Which files have been updated? I just re-installed all this last night, I'm hoping all I have to do is upload the changed files and not do another re-install (I installed and set up the adoptables part, not the forums, didn't touch those yet). Can you list which changed files I need to upload?

Well you need to replace all files that work with cookies, the following four I believe:
functions/functions.php
login.php
logout.php
register.php

Also go to phpmyadmin and add a new column 'session' with the type varchar(100) in table prefix.users.

Thanks, appreciate :)

I'm having the same issue.

umm... Can you possibly try to clear up cookies and browser cache? Perhaps it has something to do with your cookies settings, but I am not quite sure about that. I tried it multiple times on my dev demo site(which actually is a fresh install), and never had problem logging in. And btw, how long does it really take you to be able to log in after registration?

Nope I cleared my cache and cookies and the same thing.

Maybe you will have more luck with it.

adoptable site

It does not work for me either, umm... Can you go to the table prefix.users and see if a session string is inserted into the column 'session'? Or if possible, take a screenshot of it so I will get a detailed view of what is going on.

Wait let me mess with this a sec.

umm... What problem did you find?