I had similar problems, also running PHP 7.2. (500 error bringing down site as soon as the updated plugin was installed)
I opened a support ticket but did not get a response.
Here’s a sample from my error logs:
PHP Fatal error: Uncaught RuntimeException: Error while making 'tickets-plus.main': 'tickets-plus.main' is not a bound alias or an existing class. in .../plugins/event-tickets/common/vendor/lucatume/di52/src/tad/DI52/Container.php:348
Stack trace:
#0 ..../plugins/event-tickets/common/vendor/lucatume/di52/src/tad/DI52/Container.php(281): tad_DI52_Container->resolve('tickets-plus.ma...')
#1 ..../plugins/event-tickets/common/src/Tribe/Container.php(176): tad_DI52_Container->make('tickets-plus.ma...')
#2 ..../plugins/event-tickets-plus/src/Tribe/Main.php(90): tribe('tickets-plus.ma...')
#3 ..../themes/theme-child/functions.php(146): Tribe__Tickets_Plus__Main::instance()
#4 ..../wp-includes/class-wp-hook.php(286): tribe_ in /..../plugins/event-tickets/common/vendor/lucatume/di52/src/tad/DI52/Container.php on line 348
The function in my installation (Stack Trace #3) was:
// Hide QR Code in Tickets
function tribe_neuter_qr () {
if ( class_exists( 'Tribe__Tickets_Plus__Main' ) ) {
$qr_class = Tribe__Tickets_Plus__Main::instance()->qr();
remove_action( 'tribe_tickets_ticket_email_ticket_bottom', array( $qr_class, 'inject_qr' ) );
}
}
add_action( 'init', 'tribe_neuter_qr', 10 );
I did not have an opportunity to test with that function removed; I needed to get the site back up and running so I just disabled the plugin and rolled back.