The code has stopped working

Hello,
Why did the following code stop working?

add_filter( 'tube_vc_filter_post_pre_insert', 'my_tube_vc_filter_post_pre_insert' );

function my_tube_vc_filter_post_pre_insert( $my_post ){

  $my_post['post_content'] = '';

  return $my_post;

}