Visual Studio 2015 not showing Debug Source Files for any solution

Question

When I show any of my solutions' properties and navigate to Common Properties -> Debug Source Files, all I see is the list of projects and their configurations, the same as the Configuration Properties -> Configuration settings. According to @HansPassant below, this is the Configuration Manager that's showing up in both places. As I change back and forth between the two settings, all that changes is the three controls (Configuration, Platform, "Configuration Manager...") at the top of the window are disabled when I'm in "Debug Source Files". I've provided screenshots at the bottom of the question.

I restarted Visual Studio, removed my old and new .suo files, and confirmed that a teammate sees the same behavior for an entirely different solution. These solutions all worked fine under 2013 and earlier. How can I get this back? It's preventing me from setting breakpoints on external code.

Update

I did a repair of Visual Studio 2015, and the required system restart, and it didn't make a difference.

Update 2

I did a complete uninstall (which took multiple attempts, and eventually uninstalling from a system account), and reinstall, as well as installing all important (and most optional) Windows updates. There is still no difference.

Answer 1

After working with Microsoft support, we landed on the solution (which I asked them to pass along as a bug): you need to install the Common Tools for Visual C++ 2015. You can modify your installation to add this, and (for me) it didn't require a machine restart.