max_input_vars

max_input_vars is PHP parameter which defines how many variables can be added into instance, parameter is implemented into server settings setup for security reasons. Its value is set up on server by hosting. In PrestaShop it defines how many strings can be translated. In case number of strings in theme or modules is larger than that set up on server, warning arises:

Value is updated in Host settings, i.e. use Hosting account cPanel to increase it, usually Host provides instructions on this parameter customization. Alternatively, you can add php_value max_input_vars XXXX to .htaccess in root directory of your site, where XXXX is the number required on screenshot. We strongly recommend contacting hosting provider directly in case this warning occurs on server.