Hi,
Sorry for the issues on this.
I can help resolve this. The function giving the fatal error, tribe_events_single_event_meta() was deprecated 14 months ago in 3.6 and removed in 3.11.
To fix this you need to update your custom template single-events.php in your theme.
You want to replace:
echo tribe_events_single_event_meta();
with this function:
tribe_get_template_part( 'modules/meta' );
Let me know if that resolves the issue for you.
Thanks