I have a really big problem. I can't login to my site, everyone can't login to my site. If I try to login, I type all information in (Informations are right) and after pressing sign up, I will come back to index.php without logged in or any kind of a error message. Also If I try to register (feel free to try it too) it won't work. I checked my database because I thought the problem is there but the database work sucessfull. I don't know now what I can do now. Or where the problem is. Do you know where the problem can be? Also did you have this problem before at someone else?
My broken website: