I am going to be mad. I wasted 4 hours due this error but I can't solve it. When I want to create a category, wordpress give this error.
I deleted each file in my theme, but I can't found where is the error. Also I create functions-admin.php. İf you have a idea for where is the error, just tell me I will care of thats file.
Also, it's working my free host and local host. But in the different servers I took this error.