When trying to log in I am seeing the following error message:

JAuthentication: :authenticate: Failed to load plugin: plgauthenticationcookie

I am not able to log into the front or back end with any users.

I started seeing this after moving the DB to a different schema on the same server. I can log into the DB and confirm that the users all exist in the users table.

Does anyone know where I should check to try to fix this problem?

Joomla Version 3.1.5

3 Answers 3


First of all: Why on earth are you using Joomla 3.1.5? Current version is 3.3.0 and there are several security issues fixed since your version. You should update as soon as possible, which means you should do it yesterday. No excuses.

As for the message. It's coming from the remember me plugin. Joomla tries to load that plugin and fails for whatever reason. You can disable the plugin which should remove the message as well (since Joomla no longer tries to load it). However the "remember me" checkbox will no longer work.

Why the plugin doesn't load is hard to know. You could check the PHP error log file to see if there are any other messages.

Best bet is to update your installation. Did I already mention that you should have done this already half a year ago?

  • Well, how can he disable the plugin if he can't log in? Did I already mention already that he can't log in? :)
    – user5549
    Commented Jul 9, 2015 at 13:54
  • 1
    Rename the plugin folder or disable the plugin in the database directly.
    – Bakual
    Commented Jul 11, 2015 at 21:09

I had the same problem with my website. This problem shows up if you have the authenticate plugin in your database table but its not installed in the backend.

This condition can happen, if for example, you used an old database and a new theme. The new theme may not support the old plugin, so, its files will be missing.

You should either :

  1. Disable it on the list of plugins from joomla backend (search for its name in the plugin list)
  2. Check in an old version of the website files for the plugin and upload a copy to the website via FTP or file manager.
  3. Search for the plugin in JED and install it to joomla
  4. Disable/delete/ it from the database (Keep a backup!)
  • so how do you do this if you can't login to the administrator? Commented Sep 28, 2021 at 16:19

Your plugin's folder is corrupted reload it from a backup. This happened to me when I accidentally moved the plugins folder into the templates folder in filezilla lmfao.

  • I moved the plugins folder back to the root and everything went back to normal Commented Jul 10, 2019 at 18:12
  • Please edit your post to move your comment into the answer. And please take the tour. Welcome to JSE and thank you for contributing. Commented Jul 10, 2019 at 21:57

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