Do I need the cache directories from old versions of IntelliJ IDEA?
Solution 1:
You don't need these directories and they can be safely deleted. In my case, these directories appear to have been cleaned up automatically for me for past versions as I only have the latest version's folders. I'm not sure whether this is from using Toolbox to manage my JetBrains app installation and upgrade process, but either way the old folders can be safely deleted and they will be re-created if you happen to open an old version of the app.