General Support - File Size Upload Limit

File Size Upload Limit

File size upload limit is a known issue and is not related to the plugin you are using, but to your server configuration

There are many posts on this issue over the network, such as
http://www.wpbeginner.com/wp-tutorials/how-to-increase-the-maximum-file-upload-size-in-wordpress/ - this is a good article
http://www.elegantthemes.com/blog/tips-tricks/is-the-wordpress-upload-limit-giving-you-trouble-heres-how-to-change-it - another good article

Checking PHP.ini FIle limit

You can check these options using this plugin:  https://wordpress.org/plugins/wordpress-php-info/

This can be related with the following php.ini options:
- max_execution_time which is set to 120 seconds 
- max_input_time which is 60s 
- upload_max_filesize which is only 20MB