Recently I installed Umbraco forms (via NuGet) and immediately after installing it the backend broke... badly.  All the sections in my site vanished and nothing worked anymore, as seen below.  If you have a similar issue then read on as hopefully, this guide will save you some time.

First I checked the logs and error was being thrown

If you have this issue and you are using dependency injection/Autofaq, then you will need to register the Umbraco Forms assemblies with your DI container.  If you don't know where this is in your project I suggest you start looking in your Global.ascx

To register articulate with Autofaq within your DI set-up, you will need to add some code similar to the snippet below:

After recompiling my project, my backend worked. Enjoy.