ERR_TOO_MANY_REDIRECTS when trying to log into wp_admin

The session plugin doesn’t do any sort of redirect on its own, so I’m confused as to how you were able to identify WP Session Manager as the culprit here. Not saying it’s not, but I don’t see how it could be.

As this is literally a problem I’ve never seen before anywhere else, I can’t even attempt to reproduce without further information.

– How did you track things down to the inclusion of WP Session Manager?
– What other plugins are installed?

I tracked itdown by commenting out the following line in Participants Database:
require_once self::$plugin_path . ‘/vendor/wp-session-manager/wp-session-manager.php’;

This caused the redirect issue to go away.

To verify, I deactivated Participants Database and installed/activated WP Session Manager. Redirect issue came back. I deactivate Session Manager, issue goes away again.

This is with a clean WP install with only Authorizer and WP Session Manager active. I have used other CAS plugins previously, and all of them had the same redirect issue.

After looking at the code for the Authorizer plugin, I can tell you that it’s not compatible with WP Session Manager or anything that uses it. Authorizer attempts to use sessions for user state management while negotiating login, and the independent invocation of <tt>session_start()</tt> will conflict with WP Session Manager.

Said another way, only _one_ codebase can register the session handler for the system. The first to do so, wins.

Both WP Session Manager and Authorizer attempt to integrate deeply with PHP’s session system and are colliding with each other here. Unfortunately, I can’t think of a quick workaround to resolve the issue.