Getting dotted grey rectangular box when dragging fancytree node

Question

I am migrating from dynatree to fancytree-2.38.3. Everything works fine but i'm facing one issue i.e when im dragging any node from one tree to another im getting dotted grey box instead of default fancytree icons(the ones we get dragging and dropping is allowed or not). Here is the code of the tree whose nodes im trying to drag and drop

               ServerCall({
        URL : AMAConfiguration.URL
                + '/abc/def',
        method : 'get',
        data : {
            hostName : hostAddress
            },
        context : mySelf,
        callbackOnSuccess : function(options,response) 
        {
            var children = JSON.parse(response);
            
        
            $("#importedTree").fancytree({
               extensions: ["dnd5"],
              autoScroll: true,
              minExpandLevel: 3, 
              source: [children],   
              
             
            
             dnd5: {
                                
                  preventRecursion: true, 
                  autoExpandMS: 3000,           
                  preventVoidMoves: true, 
                    
                  dragStart: function(node, data) {
                      
            
                    return true;
                  },
                  dragEnter: function(node, data) {
                    return true;
                  },
                  dragOver: function(node, data) {
                    return false;
                  },
                  dragDrop: function(node, data) {
                      return false;
                  }
              } 
            });
           
            $('.importHierarchyWrapper').hide();
        },
        callbackServerCallOnFailure : function() {
            showErrorDialog();
            $('.importHierarchyWrapper').hide();
        },
        callbackServerCallOnFailureLogin : function() {
            callBackOnFailureLogin();
        }
    });

I tried changing css and giving icons path but nothing is working