I just installed Visual Studio 2015(enterprise) and Xamarin on a new Windows 7 installation. After opening an existing solution that was created in Visual Studio 2013, I now get an error stating that the shared project in the solution cannot be loaded. I opened the same solution with the Xamarin Studio on the same machine and loads correctly. After reading that you need to have the Windows 8.1 dev tools installed to get shared project support in Visual Studio 2015, I decided to reload the OS with Windows 10. I reloaded Visual Studio 2015 and Xamarin and the Windows 8.1 dev tools. And now I still have the same problem. The shared projects in a solution will not load with Visual Studio 2015. I cannot create a Mobile Application, or any other application for that matter, that contains a shared project with Visual Studio 2015.