Visual Studio 2008 design view for ASP.NET

I can not switch to design view in ASP.NET :(

Error message :-

The page contains markup that is not valid when attached to a master page.

Any idea?

Just remove the comments from the ASPX page which inherits the masterpage.

If you are using Visual Studio 2008 then update to Visual Studio 2008 SP1: http://www.microsoft.com/downloads/en/details.aspx?FamilyId=FBEE1648-7106-44A7-9649-6D9F6D58056E&displaylang=en

http://forums.asp.net/t/1197363.aspx

there is a link with somebody who has the same problem..

It appears that his problem was a "refreshing" problem.. Maybe this is your case?

Firstly try to switch to design view for your masterpage. If it succeeds, then without closing your masterpage, open your ASP.NET pages and try to switch to design view.