'Error Creating Control' ... 'true' could not be set on property

“Error creating control – [text] could not be set on property” with custom ASP.NET server controls in VS 2008 SP1

have you ever got an AJAX control error like this. I have found the same bug as of today. I have wasted almost a 2-3 hours of development before googling “could not be set on property”. simple solution is colse the VS and open the project again. seems this is bug with AJAX.

solution

1) Removing the AjaxControlLibrary.dll file from solution (and on disk), and deleting all ajax toolboxes
2) adding the AjaxControlLibrary project directly into solution.
3) close .Net, reopen and load

Also dot forget to read this KB article
http://code.msdn.microsoft.com/KB961847

Report Viewer Control missing Header Icons

Hi,
I have came accross this issue in IIS 7. You may have to configure in other IIS versions differently. Here is what I ve found.

In IIS 7, we need to make sure we configurate the ReportViewer handler.
You can follow these steps:

• Open Internet Information Services (IIS) Manager and select your Web application.


• 
  Under IIS area, double-click on Handler Mappings icon.


• 
  At the Action pane on your right, click on Add Managed Handler.



• 
  At the Add Managed Handler dialog, enter the following:
  


• Request path: Reserved.ReportViewerWebControl.axd


• Type:
  Microsoft.Reporting.WebForms.HttpHandler
  


• 
  Name:
  
  Reserved-ReportViewerWebControl-axd
  

Click OK.

Add references to
Microsoft.ReportViewer.Common.dll
Microsoft.ReportViewer.WebForms.dll
Microsoft.ReportViewer.ProcessingObjectModel.dll
in your project

and thats it
cheers