Wp admin login page does not load

I am unable to login to my wp site. My wp-admin login page does not load. Currently it is showing an error message – Warning: key() expects parameter 1 to be array, null given in /home/aletvlyt/public_html/wp-content/themes/one/framework/core/class.admin.php on line 291

I have tried changing my theme in cPanel to the standard wp theme to cancel out any issues with my current theme, but my login page would still not load.

The issue could be an out of date plugin, but I just don’t know how to fix this problem. I would appreciate any help.

My website is
http://www.aletvanwyk.com

Thanks