aman204
Hi and thank you for the support. I've just added the username and the password for the admin console of the website and also FTP credentials.
Meanwhile, I've updated all the plugins and database through the Joomla Extensions: Manage/update tub but still, nothing helped.
Currently, the website is running on Joomla 3.6.5 Maybe I should upgrade to Joomla to version 3.8.10
the only thing I'm not aware whether GK Photo template is compatible with that?