How to increase Max Input Vars
What is Max Input Vars?
It limits the number of input variables, this limitation affects $_GET, $_POST and $_COOKIE superglobal separately. In our theme, it can affect menus.
Increasing Max Input Vars in .htaccess File
The quickest way to increase Max Input Vars is editing your main .htaccess file which is usually located on the root of your FTP account and adding the next lines:
php_value max_input_vars 3000 php_value suhosin.get.max_vars 3000 php_value suhosin.post.max_vars 3000 php_value suhosin.request.max_vars 3000
If you are not sure how to locate your .htaccess you can also install a WordPress plugin only for this purpose: https://wordpress.org/plugins/wp-htaccess-editor/
Increasing Max Input Vars in wp-config.php
In this case it will need to connect to your FTP account and search for wp-config.php and add these lines at the end of that file:
@ini_set( 'max_input_vars' , 3000 );
Increasing Max Input Vars in php.ini File
In this case it will need to connect to your FTP account and search for php.ini file or .user.ini file and add these lines at the end of that file:
max_input_vars = 3000 suhosin.get.max_vars = 3000 suhosin.post.max_vars = 3000 suhosin.request.max_vars = 3000