I was tempted to downgrade the plugin, but I couldn't find a way to access older versions of the plugins so I debugged the code a little bit and found out that the following line (mb-term-meta.php:34) has to be changed so that the plugin works as expected
From: require 'vendor/autoload.php';
To: require __DIR__ . '/vendor/autoload.php';
Could you push this change and release an update?
By the way, is there a way to download a specific version of a plugin by using a parameter in the download url?