I had a problem after converting an existing project to a Web Application Project.

After conversion all "CodeFile" entries in my @Page directives where changed to "Codebehind".

At runtime I got an "Ambiguous match found" error when I called one of my aspx pages - amazingly all other pages worked correct.

I checked the namespaces in my codebehind files, restartet IIS several times, deleted the temporaray .NET files etc. - nothing worked until I changed the "Codebehind" entry back to "CodeFile". Now everything works fine again.

Does anybody know what caused that error? And I wonder what the "big" difference between "Codebehind" and "CodeFile" is ... 

Hey,

In my ASP.NET 2.0 project in VS 2005, all of my @page directives use codefile.  CodeFile is the new property for referencing code behind pages.  I don't see CodeBehind in my intellisense.

Thanks for your answer,

but the problem is:

All my page directives had the "codefile" property before i converted my VS2005 project like this

http://webproject.scottgu.com/CSharp/migration2/migration2.aspx

After conversion all props are changed to "codebehind" causing the error in one of my aspx pages ...

Hey,

Oh, your right, I didn't realize you were going to Web App project template.  Sorry about that.

I was having the same problem, then I sorted out it is version problem, as my website was built in asp.net 1.1 but I recently installed asp.net version 2.0, and that problem started right after the installaion. So to solve this problem, first I uninstalled the asp.net 2.0 then installed the asp.net 1.1 and it solved the problem.

To uninstall the asp.net use the following command on the command prompt: (windows start button -> Run -> Type CMD)
C:\WINDOWS\MICROSOFT.NET\FRAMEWORK\V2.0.50727\ASPNET_REGIIS -u
C:\WINDOWS\MICROSOFT.NET\FRAMEWORK\V1.1.4322\ASPNET_REGIIS -i

NOTE: Exact version number may differ in your case.

Although I think each new version of asp.net must be backward compatible, but its not the case.

I had the same problem just some minutes ago and I managed to throw it out using http://dotnetdebug.blogspot.com/2006/03/ambiguous-match-found-in-web-control.html 

    In short, make sure that there is not two same variables defined in the application (even different case, for example, image1 and Image1, change one of them to something else). This is causing the problem.

   Best wishes,

    Sameers