Downgrade After Effects (or any Adobe product)

A subscription to any Adobe Creative Cloud app gives you access to the latest versions of their software, meaning you can always try out all the new features, but... sometimes, just occassionally you&discover the latest version has a bug which stops you from continuing with your current project. You might even be trying to open an older project and get stuck because the features have changed and After Effects (or Photoshop, Premiere Pro or Audition) doesn&respond in the same way anymore. The solution for both is to roll back or downgrade to a previous version. For short term issues, the Creative Cloud desktop app contains an option to install previous versions but if you need to access an older version, then it is a little harder, but still possible. @AdobeVideo Big thanks to Brie from @creativecow for suggesting this tutorial!