Expedition uses APACHE as a web server and PHP as module for the scripts. By default PHP allow users to upload files with a maximum size of 2M, this can be updated by changing the PHP.ini
sudo vi /etc/php/7.0/apache2/php.ini go to line where this variable is defined upload_max_filesize = 2M and replace by upload_max_filesize = 250M
There is another parameter within that file can be increased to allow you use the multiedit with a big amount of rules
sudo vi /etc/php/7.0/apache2/php.ini go to line where this variable is defined post_max_size = 8M and replace by post_max_size = 128M
Increase the values to those variables and restart apache for the changes take effect.
sudo systemctl restart apache2