VLC won't become default for MP3 or MP4 I have tried a number of times to make VLC Media player the default for MP3 and MP4. I open a file and tick the "Always open with" checkbox, but they still open with iTunes and QuickTime by default respectively. Does anyone know how to fix this?
Try one of these 2 solutions I hope they'll solve your problem:

1-  use "Default Apps" for change every default application.



2- From the Finder, select a MP-4 file, open the Info panel (File ➔ Get Info or ⌘I), select your preferred application and then click Change All…