Problem with 'asp:ScriptManager'

Nov 4, 2008 at 11:41 PM
While upgrading from september release I have run in to this problem when I try to use the new master pages.

An error occurred during the processing of . Unknown server tag 'asp:ScriptManager'.

Any ideas?
Thanks in advance
Nov 5, 2008 at 2:25 PM
Edited Nov 5, 2008 at 2:26 PM
I found a solution but no deper understanding..
The error above of course relates to Ajax and .NET 3.5 so I pasted in reference to assembly System.Web.Extensions 3.5 in web config <controls> the error then propagated to SpLeftNavigationProvider similar to the issue in this discussion .

That in turn is an error that I had from time to time in the september release.....
I solved this by running ssm install again ignoring errors and I am up and running.

It turns out that the reinstallation adds referenses to SpLeftNavigationProvider and Ajax so for example the controls part now looks like this:
        <add tagPrefix="asp" namespace="System.Web.UI.SilverlightControls" assembly="System.Web.Silverlight,Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
        <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />

This also relates to the known issues here

Anyone that got some light that can explain this to me?

regards and  great work with the new release:

Dec 16, 2009 at 1:32 AM

Just in case others run into this issue, I just received this error after what I suspect (cannot confirm) was from a Windows Update (The KB's are listed below).  For some reason the <controls> section of web.config was empty.  Adding the controls back as stated above seems to clear the issue up.


Dec 16, 2009 at 4:32 AM


It means applying these updates may cause anyone to loose controls entry from web.config?

If that is happening then thanks for your great information.


Dec 17, 2009 at 12:23 AM

Sorry for jumping to conclusions.  No, it wasn't the KB that did it.  I just rolled back and reapplied the KBs and the web.config control elements are still there. 

I'm not sure what spontaneously removed them.  The only other thing that comes to mind is the install of Expression 3 encoder and the MediaEncoder 3 service from the PKS kit.  As with any beta, the code is a bit fragile so I'll have to be a bit more thorough in my incremental testing as I make tweaks here and there.