VS2008 compile error: cannot find class name

If the project was converted from VS2003 to VS2005 or VS2008, you can get a compile error on Global.asax and various controls and forms.

Check if the class is declared as a partial class. If yes, then see if the asax (or ascx) is using "Codebehind". Try changing that to "Codefile".

Other notes here. And notes about Global.asax in ASP.NET 2.0.