iTunes adding folders
I have happily used iTunes on Windows (now using W11) for years. I have a problem not encountered before with a folder containing 200 subfolders with ALAC or AAC tracks from (classical) CDs - c 3,200 tracks (files). When I "add" the main folder, 10 of the 200 will not load - and at least one subfolder only adds a couple of tracks (from 12 on the subfolder). I can play the "bad" tracks (the ones I cannot add) on Windows Media Player, but not on iTunes. I suspect this has to do with folder and file names: I can edit any of the addable folders but Explorer will not allow me to edit any of the files or folders that won't upload (add). This problem may have nothing to do with iTunes and be a Windows problem, but anyone with an idea of how I can get to the bottom of it so I can clean up the problem and add the missing folders to my library would be very much appreciated.
Windows, Windows 10