MediaBay not consistently loading HALion SE presets

A good number of HALion SE presets listed in MediaBay will preview/load as expected, but many won’t. Double clicking on these non-loaders does nothing; No error message even, just nothing. …It’s not just a small number that don’t work; It’s a lot.

What is going on and how do I fix it?

Win 10 Pro / Cubase Pro 12