The functions CFURLGetFSRef and CFURLCreateFromFSRef have deprecation warnings that say "not supported". That confuses me, because when I see "deprecated" I think "it may stop working at some point in the future", and when I see "not supported" I think "it doesn't work now". Which is it?
Where do you get each ?
I think both are correct, and not supported (in a certain OS version) is just a deprecated that has come to an end.
In any case, you should not use anymore.
FSRef is also deprecated (and comes with the warning that it's not on friendly terms with APFS), so the question is: where are you getting your FSRef?