I' m trying to login in Joomla Administrator (Joomla 3.5) and I am getting this error:
Fatal error: Call to a member function isAdmin() on null in /var/www/html/plugins/system/stats/stats.php on line 87
I searched about this error but found nothing helpful.
Any help or suggestion will be appreciated.
I recommend running a backup and then upgrading to the latest version of Joomla (currently v3.6.5).
If this does not fix the issue, then try the "Reinstall Joomla core files" option in the Joomla Update component (see below).
If you can't access the back-end you may need to use a manual install method such as the one described at: https://docs.joomla.org/Updating_Joomla_(Manual_Method) or something similar.
