Ensure the download completed fully; M4V files often use H.264 codecs which provide high quality but can result in large file sizes.
Popular options like VLC Media Player , RealPlayer, and MPlayer support the format. Conversion and Editing Download File Misti 6-.m4v
If the file won't open or appears broken, it might be corrupted. Ensure the download completed fully; M4V files often use H
Offers a Convert/Stream module to change formats for free. Ensure the download completed fully