So, many AVI players for Mac including QuickTime player can't play all AVI files since they don’t possess all types of AVI codecs. Why AVI Files Won't Play on macOS Sierra?ĪVI is not just a video file type, in fact, AVI video file comes with several supported formats of codec like Xvid, DivX, MJPEG, MPEG-1, MPEG-3, MPEG-4, MPEG-H, MPEG-HD, etc. avi could not be opened' etc.Īlso, it is noticed that QuickTime won't play AVI videos on Mac after you upgrading to new Mac OS X like Sierra. Sometimes, you cannot play AVI videos on Mac using QuickTime player and each time when you try to open those AVI files, you come up with different error messages like ' File Format not supported', ' Not a valid AVI file', ' The. What should I do to play AVI files on macOS Sierra? Please help me.”
After upgrading to Mac OS Sierra, I am unable to play those AVI files. “I have a few old AVI video files on my Mac.
