After migration ASP.Net 1.1 to 3.5: TreeView control is not displaying data in hierar

[na_atheeq]

Hi,

Before migration: Existing application (running on .Net 1.1) is using custom control developed by inheriting TreeView control of Microsoft.Web.UI.WebControls and displays data (country & its city’s) in heirarchical format.

After migrating existing application: the same custom control is not displaying data in hierarchical format, only country node is being shown (city nodes are not shown), I mean +/- icons are not being shown. Any idea what could be the problem?

Additionally I would like to highlight points:
• Custom control in design view (application *.aspx page) is rendering with Error Creating Control object reference not set to an instance of an object.
• But I have checked assembly reference is correct. Note: reference I have done is using @Register tag in web page (Source section).

Thanks.

Regards,
Atheeq