4.3 to 4.4 login

So I updated my nopcommerce from 4.3 to 4.4 and the home page comes up but when I try to login to admin I get this error

http://test.headznthreadz.com/login?returnurl=%2F
HTTP 400 Bad Request.  

I can't figure out what the heck is causing this

Try:
Ctrl-F5
Incognito mode
Clear cache and cookies

nope did not work

Please double check the admin role are assign and check the CRED of that User

and also please try to trouble shoot with POST Login method
as from upgrade some thing might be missed or condition missing due to that also happen

or get more brief about issue so can suggest more regarding that