Generation of designer file failed: Unknown server tag 'asp:WebPartManager'

Hi,

I recently rebuilt an application using the new Web Application Project in Visual Studio (rather than the previous Web Site Project).  I am using the January Futures CTP of Ajax and Webparts, (not to do anything with Ajax yet, just to fix drag and drop across
browsers).

A Web Application Project creates .designer.cs files for all of your aspx pages.  I am getting a warning on pages that contain an asp:WebPartManager or asp:WebPartZone control:

Warning   Generation of designer file failed: Unknown server tag 'asp:WebPartManager'.

 

 

Now if I try to add other controls to that page, Visual Studio can’t update the .designer.cs file for that page and I end up with errors.

I have seen many posts about correctly remapping web.config to use the Microsoft.Web.Preview assembly, and that does not seem to be my problem.  I have that set up as recommended and my code executes fine until I try to add new controls to my page.  I have
moved the Microsoft.Web.Preview.dll to my bin and added a reference.

Any idea why Visual Studio is having this issue?

 

Thanks,

Graham

Do you also have a reference to system.web.extensions.dll? I beleive the preview assembly has a dependency on this dll.

Hi,

I have similar problem with WAP project with custom control. Controls other than AJAX enabled work fine. However, the accordion control of the AJAX control toolkit gives me:

 Error 1 Element ‘Accordion’ is not a known element. This can occur if there is a compilation error in the Web site. 
Warning 2 Generation of designer file failed: Unknown server tag ‘ajaxToolkit:Accordion’. 

 My customer control does not have a web.config. That is in the root and my custom control is a subproject.

 I have the ajaxcontroltoolkit in the bin and the system.web.extensions.dll in the reference.

Jelle

Answer to the problem of Ajax is next:

I did not install the items in the toolbox so the designer IDE did not find them. Read the instructions on the ajax control toolkit website how to add the controls to the designer. This did the trick for me :-(.

Jelle

What instructions are you referring to?  Can you provide a link?  I looked through the site, and couldn’t find anything in the installation instructions that said you explicitly needed to add the controls to the designer.

I am still getting the errors:

Generation of designer file failed: Unknown server tag ‘asp:ScriptManager’

and

Generation of designer file failed: Unknown server tag ‘asp:WebPartManager’

 

 on any page that contains those controls.  I have Ajax 1.0 and January Futures CTP installed, and my web.config looks exactly like the one that came with the CTP, and my site is using Web Application Project.  I have exhausted every suggestion from other
forum posts such as Reseting the Toolbox, opening all your masterpages at the same time, making sure I have proper references to System.Web.Extensions.dll and Microsoft.Web.Preview.dll, etc.  Nothing gets rid of the error.

If I manually keep the designer.cs file up to date, then the appliction works fine.  That makes me think there is not a problem with my references, just something wrong with VS.

 

In addition to what is mentioned above, I had to remove this line of code: 
<cc1:ToolkitScriptManager
ID="tsmScriptManager"
runat="server"></cc1:ToolkitScriptManager>

Then click and drag the ToolkitScriptManager from the toolbox back onto my page for it to work correctly.

VS is a bit buggy with ajax control toolkit.

Mine works now though. Good luck.

JustinCM83

In addition to what is mentioned above, I had to remove this line of code: 
<cc1:ToolkitScriptManager
ID="tsmScriptManager"
runat="server"></cc1:ToolkitScriptManager>

Then click and drag the ToolkitScriptManager from the toolbox back onto my page for it to work correctly.

 

Thanks, this fixed it for me!! after an hour of searching

 

 

 

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