allowDefinition='MachineToApplication' msbuild error

Question

We have a ASP.NET MVC with 4-5 different build configurations. Whenever we change the build configuration, we need to delete the obj folder for the web project, since we get

Answer 1

I don't know that there is an "official" fix as it just seemed to start on multiple projects of mine for no reason that I can find in Visual Studio Premium 2012 (never happened in previous versions of VS).

As a work around to automate the deletion of the obj directory as others have said, similar to an answer by user Casual in this post VisualStudio: How to save the obj folder somewhere else, where unfortunately just moving the location of the obj folder didn't always seem to work.

Instead I added a few commands under Build Events in the Pre-build event command line:

rd "$(ProjectDir)obj" /S /Q
md "$(ProjectDir)obj"
md "$(ProjectDir)obj\Debug"
md "$(ProjectDir)obj\Release"

You can change/add/remove subfolders to match your custom build configurations using the line where buildConfigName matches the name of the build configuration you are using:

md "$(ProjectDir)obj\buildConfigName"

Hope this helps!