Hi everybody,

Joomla: 1.5.23
JMS: 1.2.57
Patches: 1.2.64

I get a blank page when I try to log into the backend. In addition, the servers throws this error:

Call to undefined method stdClass::onAuthenticate() in ../../libraries/joomla/user/authentication.php on line 121

Has anybody an idea what might be the problem and how to solve it? It's pretty lame not to be able to access the admin area

Best
fw

I suspect that you have a plugin that is used during the authentication and that has an error.

The line 121 call a plugin that does not has this authenticate fucntion.

To know the plugin that cause the problem, I suggest that you add a debug trace to display the name of the plugin that cause the error.
If you want that we have a look on your server and add the trace to get more info, this is possible with our billable support that you can order at
www.jms2win.com/en/joomla-multisite?page...35&category_id=1

I had the same issue some time ago. Problem was that I had an authentication plugin installed in the slave site which I had previously deleted in the master. Solution was to uninstall the plugin in JMS as well.