I've enabled Enable Edit and Continue on the Web Properties page and it's also enabled in my configuration, yet Visual Web Developer 2008 Express Edition refuses to allow me to edit source files of an ASP.NET MVC project. I can edit the aspx file with no problem though.
Any ideas what's wrong or what's missing?
If you are targeting x64 or Any CPU on a 64 bit machine you cannot use edit and continue. It only works when you are targeting x32.
I set my Platform target to x32 for the Debug configuration for this reason.
You have to enable this on two places. See this blog post about Edit and continue for Web Application Projects (WAP)
To anyone running Vista 64 bit...
It may be that the IDE is not ready for Edit and Continue (EnC) web apps on Vista 64 bit without a tweek.
My situation: Migrated Web App to Vista 64 bit. Set platform to x86, set EnC in Tools/Options & Web properties, Debug flag in Web.Config, Debug mode set in Build configuration, etc, etc.
No joy - Could hit break points, inspect variables, etc, but could not EnC.
There were 7 Google hits on Msg "Changes are not allowed if the assembly has not been loaded". No new advice there for this situation though.
After trying numerous things finally tried changing the Build output path from "bin\x86\debug" to "bin\".
There was great joy across the land - Debug with EnC works now.