Here solution if you get this Joomla! Error l :
Error Loading Module MySQL server has gone away ....
The "MySQL server has gone away" error generally means that there is a problem with MySQL on the server, therefor it is unavailable for use. In our testing environment, we shut down MySQL and received such a warning.
You should contact your current web hosting provider with the necessary details for more help with this. Most often, if Joomla has been working fine and suddenly stops working due to a database error, there is a problem with the database on your server. You'll want to contact your hosting provider for further assistance. If you have recently made a change to Joomla and then you begin to see database errors, instead of contacting your host you should first check your database settings in your configuration.php file.