[LDView] Extra search directories not working?

[N. W. Perry]

I have a number of extra search directories set in my preferences, but LDView does not appear to be searching them so all those parts are missing. I know the directories are valid because if I set one of them as the main ldraw library, its parts (and only its parts) will appear just fine. Have I forgotten to tick a simple box somewhere, or is something amiss?

This is LDView 4.4.1 on MacOS by the way.