I installed Unity 2018.3.2f1 via the Unity Hub. The install directory was D:\UnityHub\Unity2018.3.2f1\ Later I needed to go back to Unity 2018.3.0f2 for a different project. This is a downgrade, so I wanted to keep my 2f1 version installed. Because 0f2 isn't in the Unity Hub (why is it not?), I had to download the Unity Download Assistant from the Unity website. The Unity Download Assistant had a default path: D:\UnityHub\Unity2018.3.2f1\ that looked like what I wanted, but upon further inspection I realized the default install installs to the 2f1 directory!!!! There's no warning or anything, it just plows over your other install. Unity Hub is none-the-wiser about this newly installed version, and just keeps showing 2f1. Why does Unity Download Assistant suggest a folder that is for the wrong version? I like that it found my default directory that UnityHub uses, but it needs a subdirectory that matches the version of Unity it's actually installing!