We have a simple web page which displays a treeview ( Microsoft.Web.UI.WebControls )
Now, on some machines (mainly the clients ones ;-) ) the treeview isn't rendered properly :
I've tested this on all my machines, even linux, and everything is rendered correctly here. I can reproduce this error though by removing or renaming the 'webctrl_client' folder.
I don't understand however what this problem can be? The 'webctrl_client' folder is correctly installed in the root www folder, and the .dll is also properly placed? I tried clearing the browsers cache but that doesn't seem to have any effect either ....
Doen anyone have any idea what could be going on?
Microsoft.Web.UI.WebControls.Treeview is an obsolete control.
The most likely reason why your tree control breaks is that it does not work on Windows 8/IE10.
Best option is to convert to System.Web.UI.WebControl.TreeView
Quick fix: add the following code to your Global.asax.vb.Application_EndRequest. This will force IE to load your application in compatibility mode.
Try
Response.AddHeader("X-UA-Compatible", "IE=5")
Catch ex As Exception
End Try
You may also read this article on how to make sure your server recognizes IE10: http://www.hanselman.com/blog/BugAndFixASPNETFailsToDetectIE10CausingDoPostBackIsUndefinedJavaScriptErrorOrMaintainFF5ScrollbarPosition.aspx
More explanation:
Microsoft removed support for HTC behavior files in IE10 (https://msdn.microsoft.com/en-us/library/hh801216(v=vs.85).aspx). HTCs was the old way of extending browser's capabilities. Microsoft TreeView uses HTCs (found in webctrl_client folder) with no fallback. Other browsers do still seem to support HTCs.
来源：https://stackoverflow.com/questions/15927236/microsoft-web-ui-webcontrols-treeview-not-rendering-on-some-machines