For whatever the worth, I found out the hard way, that the Previews component has a NASTY habit of running into path length issues, if you have any kind of character length to the folder where you have it installing stuff, as specified in the options within Native Access. Windows has an internal limit for how long a file/folder path can be, and it seems Previews has some paths it attempts to write during install, that are already pretty close to that max, and if your content path name is anything beyond a pretty small number of characters, then the Previews install will fail.
SO - I ended up renaming that content folder, from Native Instruments, to NI, and then the Previews component was able to successfully install, HOWEVER I then had to do the Relocate process for all of the already installed components, to get each installed component to be able to find its library again. I have and now Komplete 11 Ultimate, so there are quite a few components to work through, but it doesn't take too long to do the Relocate process, to fix connection between each component and its library.
Bob Bone