Crikey error on Admin plugin upon login - found a fix

I am developing a Grav site and it has been working perfectly on my localhost and usually works well on my host (Wirenine). A few times now upon logging into the admin panel I would get an error that looked like this:

Whoops\Exception\ErrorException thrown with message "Call to a member function content() on null"

#0  in /home/ffcmsbiz/public_html/ Twig.php:300

 Open: /home/ffcmsbiz/public_html/ Twig.php

        public function processSite($format = null)
            // set the page now its been processed
            $pages = $this->grav['pages'];
            $page = $this->grav['page'];
            $content = $page->content();
            $config = $this->grav['config'];

I have several sites on Wirenine and two of them had this error, three of them were fine. After much trial and error I finally got logged in by deleting my user/admin.yaml file and creating a new user from command line: bin/plugin login new-user. After that I was able to get logged in and everything is just fine. I am not sure why this happened, I did notice that the create user process has been updated adding an enabled or disabled switch. This has happened intermittently on two different sites for a week or so now. It is working fine now so I hope this helps anybody that comes across it.

Please create an issue for this here:

I did, I thought I would put it both places just in case.

This issue keeps rearing its ugly head. I was out for a few hours, came home and tried it again and same error. Will post the the github any information I gather,.