I have problems with upgrading to the newest Vuforia plugin for Unity in Windows 10. If I install the Vuforia plugin using the Unity installer, an older, 7.x version gets installed. That works all right, however, the Asset Store samples (in particular the Vuforia Hololens sample project) require Vuforia 8. However, once I install the latest version (8.0.10), Unity will no longer recognize that Vuforia is installed. There is no "Vuforia" submenu under "GameObject" or "Help", and the Vuforia namespace is not visible either.
After some research I found out that the Vuforia plugin gets installed to /Path_To_Editor/Editor_Version/Editor/Data/PlaybackEngines/VuforiaSupport/. I could verify that the version 8.0 installer works, because that directory gets completely replaced during installation. Replacing that directory with the previous version (7.x), after restarting Unity, Vuforia gets detected again (albeit as expected, as version 7.x). For some reason the contents from the 8.0 version won't be detected.
I have the same problem with Unity 2018.2.14 and 2018.3.3. Any ideas what's happening here?