Sometimes Visual Studio likes to be stubborn and break the toolbox when I've been screwing around with custom controls.... (like the following screenshot) where no matter what you do, you can't drag 'n drop the built-in controls (like a CheckBox or Button).
found out via a old blog post (will edit later to link original post) that you have to delete a couple of files in your localappdata folder :p
so I made a small powershell script that automates it for you and deletes those files on every version of visual studio that is setup under the current account :3
Fix Broken/Blank Toolbox in Visual Studio. GitHub Gist: instantly share code, notes, and snippets.
















