Ticket #24062: 24062.3.diff

wp-includes/js/media-editor.js

@@ -539 +539 @@
                 add: function( id, options ) {
                         var workflow = this.get( id );
 
+                        if ( workflow ) // only add once: if exists return existing
+                                return workflow;
+
                         workflow = workflows[ id ] = wp.media( _.defaults( options || {}, {
                                 frame:    'post',
                                 state:    'insert',