Based on inline comments, the posts_where filtering applied by The_Events_Calendar::events_search_where is "for standard wordpress templates." However, it is also applied to the "Edit Posts" listing in wp-admin, and breaks at least one plugin (Role Scoper) there.
In my trial, I achieved a workaround by changing code as follows in the-events-calendar.class.php:
add_filter( 'posts_join', array( $this, 'events_search_join' ) );
add_filter( 'posts_where', array( $this, 'events_search_where' ) );
add_filter( 'posts_orderby',array( $this, 'events_search_orderby' ) );
add_filter( 'posts_fields', array( $this, 'events_search_fields' ) );
add_filter( 'post_limits', array( $this, 'events_search_limits' ) );
to:
if( ! is_admin() ) {
add_filter( 'posts_join', array( $this, 'events_search_join' ) );
add_filter( 'posts_where', array( $this, 'events_search_where' ) );
add_filter( 'posts_orderby',array( $this, 'events_search_orderby' ) );
add_filter( 'posts_fields', array( $this, 'events_search_fields' ) );
add_filter( 'post_limits', array( $this, 'events_search_limits' ) );
}
Can you confirm that's a harmless change, and if so roll it into your trunk?