on my mac
SketchUpQL.qlgenerator v3 from SU v19 works but
SketchUpQL.qlgenerator v4 from SU v20 fails…
# renaming the folder
/Applications/SketchUp 2020/SketchUp.app/Contents/Library/QuickLook
# to
/Applications/SketchUp 2020/SketchUp.app/Contents/Library/QuickLook!
and restarting the mac seems to fix it…
john