AdminCP Redirect Not Working

[Abronsyth]

No, HoF, I haven't actually touched the Mys 1.3.4 script in a bit, but when I had the script installed before (though that was a little while ago) it was working perfectly, and had worked since the transfer. Now I can't seem to get anything to work right! After re-re-reinstalling I now get this error when trying to log in, so I can't quite tell if I've fixed the redirect error or not;
http://i.imgur.com/g7viHua.png

I even double checked the password and everything in phpMyAdmin, and I am still getting this error.

And, when I try to register a new user;
http://i.imgur.com/u9jIhiR.png

I honestly have no idea what's going on. It worked fine before I installed a fresh version of the script. PHP version is fine, as is everything else as far as I can tell.

Edit;
Ohhh wow, I just looked at database and my adopts_users is all messed up. It put my admin account in as user No. 2 and my test account- which it originally said didn't work- in as user No. 1, and used the same email for both, despite me using different emails for each.