title: MacOS/VisualStudioCode/Omnisharp missing .NET Framework 4.6.1
body: <p>I'm on macOS Catalina running:</p>
  <ul>
  <li>vscode 1.48.1</li>
  <li>ms-dotnettools.csharp 1.23.1 (which is omnisharp underneath)</li>
  <li>Visual Studio For Mac 8.7.3</li>
  <li>Mono MDK 6.12.0.91</li>
  </ul>
  <p>I have a project that targets .NET 4.6.1. I use vscode for this project. I also have another project that uses Visual Studio For Mac for Xamarin reasons. Unfortunately, it seems that the later versions of Visual Studio For Mac require at least Mono MDK 6.10.x. That version doesn't appear to support .NET 4.6.1. This means Omnisharp can't load the projects for vscode project. I've tried downgrading the Mono MDK without success for the vscode project. All my googling gets  me to the download pages for the developer packs for Windows that have .NET framework 4.6.1, which are useless, or ways to force Omnisharp to see a 4.6.1 framework at some other path by setting an environment variable, <code>FrameworkPathOverride</code>, to the appropriate place, which doesn't exist on my system. At this point the only path I can see is to retarget my 4.6.1 application to a later framework but that will take forever. All I really need is a 4.6.1 framework for macOS. Halp?</p>
  <p>EDIT: Yes, I know .NET is for Windows and Mono is for everything else. Mono provides compatibility with .NET versions and Omnisharp has handled this properly in the past. The problem only appeared after updating Visual Studio For Mac and the Mono MDK.</p>
  <p>EDIT: Solved, see accepted answer for details</p>