Snapshot Pro site cloning fails (error 500)

Hello

I can't take snapshots from any of my sites that have actual contents with Snapshot Pro plugin. The plugin starts to work, but after a quick while it crashes with error 500 (internal server error).

I have studied the thread at
https://premium.wpmudev.org/forums/topic/500-internal-server-error-on-my-wordpress-website#post-992695

and made sure that there is certainly enough memory in the wp-config.php. It is set currently as:
define( 'WP_MEMORY_LIMIT', '32768M' );

Please advice,
- Ossi