?????"TreePanel/basic/refresh static tree"?????
???????????,????????,?????'tree.root.ui' is null or not an object ?.?????Handler="refreshTree(#{TreePanel1})??Handle r="refreshTreeExt.getCmp('TreePanel1'))??????????? ???

I found an example "TreePanel / basic / refresh static tree" of an error
The first load is not wrong, but when you click refresh, they will report " 'tree.root.ui' is null or not an object". The source of the Handler = "refreshTree (# (TreePanel1))" change to Handler = "refreshTreeExt.getCmp ( 'TreePanel1'))" was normal. Hope that this issue attention