Executable exits when loading a project

I just built the engine in VS2013 in development editor, then I ran the executable by hitting f5 in VS2013. Unreal Editor shows up and prompted me to choose a project to open. So far so good, but if I choose any existing project, like “LandscapeMountains” and click “Open”, the running editor from VS2013 will exit and instead a new instance of the editor executable is automatically launched to open the project. This makes it impossible to debug in VS2013