feedTree: amend previous to check that nodes are actually there

js/FeedTree.js

@@ -276,10 +276,12 @@ define(["dojo/_base/declare", "dojo/dom-construct", "dijit/Tree", "dijit/Menu"],
 					const node = treeNode.rowNode;
 					const tree = this.domNode;
 
+					if (node && tree) {
 						// scroll tree to selection if needed
 						if (node.offsetTop < tree.scrollTop || node.offsetTop > tree.scrollTop + tree.clientHeight) {
 							$("feedTree").scrollTop = node.offsetTop;
 						}
+					}
 
 				}, 0);
 			}