Lightroom Classic (11.4.1) imports 101 out of 540 photos, then stops. When I cancel the import I get the error message (attached a screen grab) "The following files could not be imported because they could not be read or the destination folder is not writable." I have the memory, space etc. I've tried restarting the computer, deleting all folders/files and starting the import from scratch, working with each memory card separately and I keep hitting this wall at 101 photos importing, then the importing gets hung up and I can't import the other 439 images. I tried creating a different destination folder for those 439 files, and that didn't work either. Nor did saving to an external HD.
I'm on a 2019 MacBook Pro, running Catalina 10.15.5