PHP Max Input Vars defines how many variables can be passed to a single function to avoid overloading.
max_input_vars directive must be defined in the
.htacess file on the server. The SFTP credentials in your Strattic dashboard will allow you access to these files.
Connect to your SFTP server using (see how to connect using Cyberduck)
From Cyberduck, go to the view menu and select “show hidden files”
Within the /public_html/ folder locate .htaccess
Right-click on the file and select Edit
Paste the directive code
php_value max_input_vars 3000at the top of the file. You can replace 3000 with the value you require.
Once you are done making changes save the file. The downloaded file will then upload to back to the server and override the existing file.