[christoofar]

NAS is a WD MyBookLiveDuo - 4TB - all switches are GBit, all wire is CAT6. Connection to Pioneer VSX-1120 is HDMI, file formats are either FLAC or high bitrate mp3.
I go to addons/Kodi repository/Skins, there is nothing there...nothing. Same when I try "Get More" under System/Skin setting

what format (sample rate and bit depth) are the files? Pioneers are notorious for having EDID issues, I wonder if Kodi is being forced to resample rather than passing natively? Or on other systems, you were resampling whereas here you are passing untouched?

Under 'Get more' was where I see the skin options. They are in the main Kodi repository, not any of the unofficial ones

All files are 44.1hz/16bit. Have been using XBMC & this same receiver for years now, have never seen this before. Video audio (at least all that I've tested) plays fine.
And yes , under "Get More" is where I went, listed every single one as being incompatible after I disabled "hide incompatible"
Also my OE version is 4.97.25.0 (and I have auto update turned on)