Login Redirection Loop

After doing a ton of research on this for a client. I found the following and hope it helps others…

On some Linux servers, not having the correct permissions on files/folders can cause a loop. Especially if your .htaccess file does not have the correct permissions (works with 644 and 755).

If the file ownership is not set correctly, it can cause a loop. One of my clients had his personal group and not the server root group on the WP-ADMIN folder and all its contents. That caused the loop in his case. Running CHOWN with his account name and the root group name fixed the problem.

And I fixed a client’s site today when I noticed that the redirect loop was going to https://site/wp-admin instead of http://. A security plugin he installed added “define(‘FORCE_SSL_LOGIN’, true);” and “define(‘FORCE_SSL_ADMIN’, true);” and he didn’t have a cert installed for his domain. That caused a loop.

Also, there’s a MULTISITE related thread with some .htaccess changes that fixed a problem on my own multisite install.