Hi,

My application need to populate a treeview with the first 2 levels of the hierarchy when I get in to the page.
In my code behind I populated the treeview with the first node and the second node as a child of the first.
For both nodes I set ExpandMode.WebService, so I can have better performance then the ServerSide when people expand the nodes. (The treeview could very big)

The problem is that when I try to collapse the first node it doesn't collapse (even if it fire the client side OnNodeCollapsing event) and if I try to click the node again it contact the WebService but it isn't able to restore the right behavior raising this JS error

'this._element' is null or not an object.

Can you help me?

There is no way to sharing Server Side creation of the nodes and WebService expand behavior?

Hi Simone Belia,

This sounds as a bug which we have recently fixed. You can try the latest internal build.
Best wishes,
Albert
the Telerik team

Hi Albert,

The behavior changed, but it didn't solve my problem.
Now when I try to collapse the node it still doesn't collapse, but when I click again the I see duplicated nodes under the one I clicked.
The error disappears, but I still have this issue.

Can you help me again?

thank you

Hello Simone Belia,

I suggest you open a support ticket and send us a project which demonstrates that problem. Once we reproduce the problem at our side we would provide a solution. Thanks.

Greetings,
Albert
the Telerik team