Fixes the Notice: Trying to get property of non-object in plugins/edit-flow/modules/editorial-metadata/editorial-metadata.php on line 634

editorial-metadata.php

function filter_manage_posts_columns( $posts_columns ) {
  	$screen = get_current_screen();
		if ( $screen ) {
			add_filter( "manage_{$screen->id}_sortable_columns", array( $this, 'filter_manage_posts_sortable_columns' ) );
			$terms = $this->get_editorial_metadata_terms( array( 'viewable' => true ) );
			foreach( $terms as $term ) {
				// Prefixing slug with module slug because it isn't stored prefixed and we want to avoid collisions
				$key = $this->module->slug . '-' . $term->slug;
				$posts_columns[$key] = $term->name;
			}
		}
		return $posts_columns;
}