I just upgraded all my plugins and upgraded to the latest version of WordPress. The website is up and running, but when I go to log in to the wp-admin I get a fatal error:
Fatal error: Call to undefined function set_url_scheme() in D:\Hosting\7326684\html\wp-admin\includes\plugin.php on line 909
I have tried going in to the files and disabling all the plugins, thinking there is some kind of weird incompatibility. When I do that, I get this fatal error when I try to log in:
Fatal error: Call to undefined function is_blog_admin() in D:\Hosting\7326684\html\wp-admin\includes\dashboard.php on line 39
I also tried disabling all the themes, but then I couldn't even get to the wp-admin to try logging in at all.
What can I do to fix it?