I am experiencing some strange behavior with a WAP in VS 2008. I have a basic website with an asp:menu, asp:treeview, master page, and content page. I am seeing an error show up in the Output window during debug. The error is as follows:

The error repeats itself several hundred times and it is causing my application to run much slower than it should. I believe it is somehow related to the SiteMapDataSource and the asp:menu control. It seems to happen intermittently, but it definitely happens everytime I debug the application. I also believe this same behavior is happening on the production server, but I'm not sure where to check for those errors. It is not throwing an error in the page. Here is a dump of my output window while I am debugging my website (there's still another 1000 lines or so, but they all have that exception). Any feedback is greatly appreciated.

Could someone please look into this issue or perhaps shed some light on this? I firmly believe the issue is using a SiteMapProvider with VS 2008 WAP. Thank you. 

I get the same error(s) in VS 2008 WAP. This is a project I upgraded from a VS 2005 WAP.

If I set the debugger in VS 2008 to throw all exceptions I get for example this exception:

Could not load type 'System.Web.UI.Label' from assembly 'System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.

and

Could not load type 'System.Web.UI.WebControls.WebParts.PlaceHolder' from assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.

and

Could not load type 'System.Web.UI.PlaceHolder' from assembly 'System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.

..to name a few

 I don't have any SiteMapProviders configured nor do I have a SiteMap xml or SiteMapDataSource

Could this be some configuration problem in web.config (since I upgraded from a VS 2005 WAP)

Can we ask for a reply from an MS person or MVP?

Is your project targeting 3.5 or 2.0 framework? If 3.5, then you need to remove references to System.Web.Extensions 1.0 and remove dll from Bin.

I'm getting the same error, but am not referencing System.Web.Extensions, nor am I using the 3.5 framework.

So far this seems like the most promising thread I've found to resolving this issue. If I find anything more, I'll be sure to post it here.

I'm getting these errors too. The original WAP was VS2005, upgraded to VS2008, .Net 3.5.

System.TypeLoadException occurred
  Message="Could not load type 'System.Web.UI.WebControls.WebParts.Image' from assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'."
  Source="mscorlib"
  TypeName="System.Web.UI.WebControls.WebParts.Image"
  StackTrace:
       at System.Reflection.Assembly._GetType(String name, Boolean throwOnError, Boolean ignoreCase)
       at System.Web.UI.NamespaceTagNameToTypeMapper.System.Web.UI.ITagNameToTypeMapper.GetControlType(String tagName, IDictionary attribs)
  InnerException:

System.TypeLoadException occurred
  Message="Could not load type 'System.Web.UI.Image' from assembly 'System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'."
  Source="mscorlib"
  TypeName="System.Web.UI.Image"
  StackTrace:
       at System.Reflection.Assembly._GetType(String name, Boolean throwOnError, Boolean ignoreCase)
       at System.Web.UI.NamespaceTagNameToTypeMapper.System.Web.UI.ITagNameToTypeMapper.GetControlType(String tagName, IDictionary attribs)
  InnerException:

System.TypeLoadException occurred
  Message="Could not load type 'System.Web.UI.WebControls.Image' from assembly 'System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'."
  Source="mscorlib"
  TypeName="System.Web.UI.WebControls.Image"
  StackTrace:
       at System.Reflection.Assembly._GetType(String name, Boolean throwOnError, Boolean ignoreCase)
       at System.Web.UI.NamespaceTagNameToTypeMapper.System.Web.UI.ITagNameToTypeMapper.GetControlType(String tagName, IDictionary attribs)
  InnerException:

System.TypeLoadException occurred
  Message="Could not load type 'System.Web.UI.WebControls.WebParts.SiteMapPath' from assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'."
  Source="mscorlib"
  TypeName="System.Web.UI.WebControls.WebParts.SiteMapPath"
  StackTrace:
       at System.Reflection.Assembly._GetType(String name, Boolean throwOnError, Boolean ignoreCase)
       at System.Web.UI.NamespaceTagNameToTypeMapper.System.Web.UI.ITagNameToTypeMapper.GetControlType(String tagName, IDictionary attribs)
  InnerException:

System.TypeLoadException occurred
  Message="Could not load type 'System.Web.UI.WebControls.SiteMapPath' from assembly 'System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'."
  Source="mscorlib"
  TypeName="System.Web.UI.WebControls.SiteMapPath"
  StackTrace:
       at System.Reflection.Assembly._GetType(String name, Boolean throwOnError, Boolean ignoreCase)
       at System.Web.UI.NamespaceTagNameToTypeMapper.System.Web.UI.ITagNameToTypeMapper.GetControlType(String tagName, IDictionary attribs)
  InnerException:

System.TypeLoadException occurred
  Message="Could not load type 'System.Web.UI.WebControls.WebParts.ContentPlaceHolder' from assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'."
  Source="mscorlib"
  TypeName="System.Web.UI.WebControls.WebParts.ContentPlaceHolder"
  StackTrace:
       at System.Reflection.Assembly._GetType(String name, Boolean throwOnError, Boolean ignoreCase)
       at System.Web.UI.NamespaceTagNameToTypeMapper.System.Web.UI.ITagNameToTypeMapper.GetControlType(String tagName, IDictionary attribs)
  InnerException:

System.TypeLoadException occurred
  Message="Could not load type 'System.Web.UI.WebControls.WebParts.Content' from assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'."
  Source="mscorlib"
  TypeName="System.Web.UI.WebControls.WebParts.Content"
  StackTrace:
       at System.Reflection.Assembly._GetType(String name, Boolean throwOnError, Boolean ignoreCase)
       at System.Web.UI.NamespaceTagNameToTypeMapper.System.Web.UI.ITagNameToTypeMapper.GetControlType(String tagName, IDictionary attribs)
  InnerException:

System.TypeLoadException occurred
  Message="Could not load type 'System.Web.UI.Content' from assembly 'System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'."
  Source="mscorlib"
  TypeName="System.Web.UI.Content"
  StackTrace:
       at System.Reflection.Assembly._GetType(String name, Boolean throwOnError, Boolean ignoreCase)
       at System.Web.UI.NamespaceTagNameToTypeMapper.System.Web.UI.ITagNameToTypeMapper.GetControlType(String tagName, IDictionary attribs)
  InnerException:

Did you upgrade to .NET 3.5? If yes, please remove 1.0.x Extensions from references and from bin. Extensions 1.0 is only for stock 2.0 framework.

Hello, Mikhail.

Yes, my wep app project was upgraded to .Net 3.5. Also, I upgraded referenced web control and business logic projects in the same solution to .Net 3.5.

There are no references to system assembly 1.0 extensions and no 1.0 DLLs feature in the web app bin folder. Project properties show that System.Web.Extensions GAC 3.5.0.0 is being referenced. All other references are either to my own .Net 3.5 projects in the solution (Project Auto Update), or various system assemblies (GAC 2.0.0.0 / GAC 3.5.0.0). The only exceptions to this are App_Licenses (BIN 0.0.0.0) and a 3rd party web control (BcasicFrame.WebControls.BasicDatePicker BIN 1.25.12076).

I don't know whether this will muddy the waters or not, but something else that's a bit peculiar is going on. Due to some code design changes, I recently deleted a number of references since they are now redundant (these being Enterprise Library and a CodeSmith DLL, "NetTiers"). Although everying appears to compile and run correctly, when I run a code analysis on the web project, I get a few CA0055 errors for the WebApp project: "Could not load Microsoft.Practices.EnterpriseLibrary.ExceptionHandling.dll", "Could not load Microsoft.Practices.EnterpriseLibrary.Logging.dll" an "Could not load NetTiers.Configuration.dll". This is most strange because I can find no remaining reference in any solution project to these assemblies. I ran ILDASM on each DLL in the web app bin folder and the manifest shows no indicaton of the above assemblies. But it must be getting these dependencies from somewhere! I've done obvious things like clean the solution, re-boot, check for assemblies in all solution project bin folders, to no avail.

Thanks for any pointers.

 Mike

> Extensions 1.0 is only for stock 2.0 framework.

Is version 2.0.50727.1433 considered a stock 2.0 framework?

Has anyone found a solution to this?

I decided to start creating a project from scratch (VS 2008, ASP.NET AJAX, .NET 3.5) and still had the same problem. Everything ran fine until I started adding AjaxControlToolkit controls to the page.

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="ajaxToolkit" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <ajaxToolkit:ToolkitScriptManager runat="server" ID="ScriptManager" EnablePartialRendering="true" />
    <div>
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
        <ajaxToolkit:CalendarExtender ID="CalendarExtender1" TargetControlID="TextBox1" runat="server">
        </ajaxToolkit:CalendarExtender>
    </div>
    </form>
</body>
</html>

Thoughts?

I'm seeing this problem and I'm using just VS2005 with .NET Framework 2.0 and AJAX.

I get many, many typeloadexceptions and they are giving errors like:

Could not load type 'System.Web.UI.WebControls.WebParts.PlaceHolder' from assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'

Could not load type 'System.Web.UI.PlaceHolder' from assembly 'System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'.

Could not load type 'System.Web.UI.WebControls.WebParts.Content' from assembly 'System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.

.... 

 I'm not sure why it keeps looking in WebParts

Bubbling this up again as I don't see a resolution anywhere...

I'm having this same issue.  Things kind of work but I get about 4000 of these typeloadexception errors during the JIT compile of the website.  Funny thing is it doesn't always happen.  One time it'll JIT ok without these errors, the next it'll throw all these errors. 

 When it works ok (no errors), it JITs in only a few seconds and everything seems fine.  If it starts throwing all these errors, it can easily take a minute to JIT and display my start page.  As you can imagine, when doing agile, iterative development, this extra minute can turn into an awful lot of wasted time.

Like several others in this thread I am using the AJAX Control Toolkit.

VS2008 with performance hotfix.  (Thanks, this made a huge difference in performance!)

WinXP Pro SP2

 Is this something we are looking at VS2008 SP1 to resolve?  Or is there a workaround?

TIA,

MAC