Error 500 in Bluk Smash

Hello clopezi, I hope you are doing well today!

500 error it’s very general and can be caused by many things.

To eliminate the reasons of this, please try to increase your memory limit. Add this line inside your wp-config.php file:
define( 'WP_MEMORY_LIMIT', '256M' );

If this will not selp to solve the issue, would you please deactivate all other plugins, leave only the WP Smush activate and check if this JS errors appearing?

If all is well, activat eone plugin at the time to find the plugin that causes this conflict.

Let us know how it went!

Cheers,
Nastia