Cannot login or access dashboard after WP update to 4.4

You could create a new database, switch over your wp-config.php file for the new database (save your old database info) and see if you can get it set up with a completely fresh install/database combination. Then, it’s a very quick switch back to your older database (change a line or two in wp-config.php) to check back.

The problem is the URL that the form on the login page has. The new version generates

<form name=”loginform” id=”loginform” action=”https://www.yourdonmain.com/wp-login.php&redirect_to=http%3A%2F%2Fwww.yourdonmain.com&#8221; method=”post”>

when it should be

<form name=”loginform” id=”loginform” action=”https://www.yourdonmain.com/wp-login.php&#8221; method=”post”>

For whatever reason, it adds &redirect_to=http%3A%2F%2Fwww.yourdonmain.com which is really &redirect_to=http%3A%2F%2Fwww.yourdonmain.com

There is no ? mark which precedes variables after a script name.

A redirect on the login page wouldn’t cause a 404 error in admin areas. Once you’re logged int, you should be able to go to yourdomain.com/wp-admin and have access. That redirect is added if you are redirected from another page to the login page (for instance, if you are not logged in an try to access the admin url noted above, that will be placed there).

You all might want to check file permissions AND file ownership to make sure that’s all set right. I’ve seen WP enter a redirect loop from the admin area when perms and ownership are not set right.

I manage a multisite network and encountered the same login problems.
I downgraded to 4.3.1: same problem.
I downgraded to 4.3: problem solved, can login again.
Member gzu told me the plugin More Privacy Options caused problems. So I updated the plugin to 4.1.1. And deleted te old files from /wp-content/mu-plugins/.
I just smoothly updated WordPress to 4.4.

I am completely new to WP, indeed all I currently know how to do is set up posts and pages and new sliders etc, when it comes to the background knowledge of all of the actual proper work of writing and coding a site, I just don’t have it, however as part of a new job, I am starting to very basically take on an existing website, and I NEED HELP PLEASE.

I updated the WP to 4.4 this morning, I am experiencing the same problem as many of the people on this thread, I now have a blank white page when I try to load the website, I have no access to the dashboard, I have not got enough knowledge to go into the files on the hosting server to change them without making more problems for myself.

I have looked into the option of going back to a previous version of WP, (4.3.1 was working just fine only minutes before I upgraded to 4.4. Is there any support for someone like myself who does not know how to work this problem out?

Any advice is greatly appreciated ( I need “Dummies guide to” style advice), if that advice is to hand it over to someone who knows what they are doing then please understand I can’t do that right now. ??

It sounds like there is an issue with a plugin or theme casing a fatal error on your site. I’d recommend using FTP to edit your wp-config.php file to enable debug mode, then see if an error notice appears on your previously white screen. That should help you narrow in on the specific issue and then you can look for a solution (disabling a plugin or fixing it, for instance).

Do you have a host or third party back up system in place that can then revert to a safe point? That would be a quick fix after you debug the issue per above, then you can fix the problem before updating to 4.4 again.