RedGate VS extension update removed Visual Studio devenv.exe?

I had VS2017 open, clicked on the updates for ReadyRoll & SQL Prompt. I was then asked to close all VS instances. The update progress bars seemed to go fine, but then I got an error saying all extensions failed to update with an error log attached. I now cannot find my VS2017 executable! The VS2017 icon suddenly turned to the white Windows generic icon on my task bar after the failed install, and I could no longer run VS because it said it couldn't be found. I cannot find it anywhere in Windows Explorer in the usual location.

Also, after closing the failed install dialog I get this error in a dialog: Package Microsoft.VisualStudio.MinShell failed to install.

This is pretty frustrating, don't tell me I'm going to have to reinstall Visual Studio because redgate extensions failed to update.

I tried applying the updates via the VS2017 installer, which apparently seemed to install the RedGate products succesfully, as well as applying a general Visual Studio update to 15.2. However now when I try to open Visual Studio, I get another dialog saying "Unknown error", and VS does not start.