Hardware: Raspberry Pi 3 and PC
OS: LibreElec 8.0.1 and Windows 10
I tried this with updated and all fresh Krypton installations on Rpi3 and Windows in turns, scanned HDD folders with music files to Kodi library, created a smart playlist with criteria ‘rating:3’ & ‘greater than’, ‘limit to 10’, ‘order:random’, just like I used to do on Jarvis and it would then return a list of music just as expected. Opened the newly created smart playlist in Krypton, but the playlist returns plain empty. Everything else in the music library seems to work ok, like they did in Jarvis, manual .m3u’s, automated top100s and party playlists work without problems, it’s just the smart playlists that fail and return empty.
Can’t live without smart playlists, for me they have been the biggest improvement in music listening at home since the introduction of compressed audio files at adequate quality on computers. 
Fixes, workarounds, anybody else with this problem? Google didn’t recognize this topic, making me wonder if anybody else uses Kodi music library smart playlists, but me.
Until the smart playlists work, I’ll keep with Jarvis. Another issue for me is the new Estuary skin and the fact that it’s messy to navigate and doesn’t support all Kodi features to my experience. Tested Estuary once, saw it had several flaws and misses, went straight to Confluence and will stick to that if I’m ever to return to Krypton or anything that follows – but that’s a topic for another thread anyway.