/**
 * This code should be added temporarily to your theme's functions.php file
 * (or you could set it up within its own plugin) ... please remove after
 * testing.
 */
add_action( 'admin_notices', 'tribe_temp_debug_test' );

function tribe_temp_debug_test() {
    $query = new WP_Query( array(
        'post_status' => 'any',
        'posts_per_page' => 1,
        'meta_key' => '_EventStartDate',
        'category_name' => 'Events'
    ));

    echo '<p> </p><strong> Debug information </strong> ';
    var_dump( $query->posts );
    echo '</p>';
}