The utorrent unsupported piece size 64mb error is a clear signal that your client has aged out of the modern torrenting ecosystem. While you can tweak cache settings, update to the latest µTorrent (which still fails), or scream into the void, the only logical solution is to
pieces, which are now more common for very large files (e.g., 500GB+ torrents). Legacy Architecture utorrent unsupported piece size 64mb