Fixed it!
The developers forgot a line. You will have to edit /wp-content/plugins/jet-event-system-for-buddypress/main/jet-event-start.php.
Add the following line at the bottom of the ‘require’ strings:
require ( WP_PLUGIN_DIR . ‘/jet-event-system-for-buddypress/main/jet-events-update.php’ );
Save the file, and try to activate the plugin. It should work now…
