Why isn't Edit and Continue working in Visual Studio 2015?

Question

I am unable to get "Edit and continue" to work in Visual Studio. It fails with the message "Changes are not allowed if the project wasn't built when debugging started".

I am debugging an ASP.Net Core (1.1.0) Web API app using .NET Framework 4.6.1 and Entity Framework 6.1.3.

I am using Visual Studio 2015 Enterprise Update 3 with IIS Express.

I have Edit and Continue enabled in Tools > Options > Degugging > Enable Edit and Continue.

I have IntelliTrace set to IntelliTrace events only in Tools > Options > IntelliTrace > General. Disabling IntelliTrace did not fix the problem.

I also added COMPLUS_FORCEENC=1 to system environment variables.

Any other ideas?

Answer 1

Edit and Continue doesn't appear to be supported yet for .Net Core, at least in VS2015 U3. I've run into the exact same issue and while I can't find any concrete references for it, there seem to be hints in a number of places. Here are a couple of links that may support this claim:

https://github.com/dotnet/coreclr/issues/7902

https://github.com/dotnet/roslyn/pull/16197

I have yet to try VS2017 RC, perhaps the support is there for it there. If you've found anything else since posting I'd be delighted to hear about it.