"The player might not support the file type or might not support the code that was used to compress the file." This is the most common error when playing videos in rare formats like M4V using Windows Media Player or Movies & TV. The best solution is to change the M4V video to a more easily recognized format like MP4 and AVI. Wise Video Converter supports converting multiple video formats to and from each other, such as converting MOV to MP4, M4V to MP4, MP4 to MKV, MP4 to WebM, and so on.