I just started working on a new project and I can't set the build action to Debug/Release. This is a huge problem!
I have another solution on my system that, when opened, allows me to change the solution configuration. So it must have something to do with this specific solution?
The right solution is to:
You should see the solution configuration drop-down will be enabled
From a Google search
(from http://www.gregcons.com/KateBlog/HowDoIMakeADebugBuild.aspx, which includes screenshots)
bring up Tools, Options, and go to the General section under Projects and Solutions. Find "Show advanced build configurations" and check it.