My mp4 files are being changed to m4v when copied to an external drive, how can I stop this happening?
I bought a 1 TB external drive to store my mp4 movies on. It's accepted 80 GB of them, but any more I try to copy in are being changed to m4v files - which of course cannot be played! What can I do to stop this happening?
iMac (2017 – 2020)
