Firefox 108.0.1 (64-bit) - “The WidevineCdm plugin has crashed”

While studying for my CKAD on Udemy over the holidays I encountered this error when attempting to open ANYTHING that had DRM protected video; Udemy, Netflix, Hulu, etc. Some recommended fixes included maintaining a separate firefox binary. Luckily I found the fix on

Edited /etc/apparmor.d/usr.bin.firefox :

  1. Below the line:

    • # per-user firefox configuration
  2. Insert the line:

    • owner @{HOME}/.{firefox,mozilla}/**/gmp-widevinecdm/**/ m,
  3. After that, you can reboot your computer (or reload AppArmor’s rules with:

    • apparmor_parser --replace /etc/apparmor.d/usr.bin.firefox