Snap Firefox cannot create user data directory

This issue is only reported on firefox installed from snap. And this issue will only present itself if the user is having a custom $HOME directory.

Usually snap is configuring Ubuntu AppArmor with DEFAULT HOME DIRECTORY path for ex: /home/some_username .

But in your case if you are using custom AD integration in your Ubuntu then you may be having custom home directory like /home/local/AD_DOMAIN/username .

Possibile Fix

If you use domain with realm, so our path home is not /home , and instead home path like /home/MYDOMAINCOMPANY/.

You need to edit your /etc/apparmor.d/tunables/home.d/ubuntu and add below line:

@{HOMEDIRS}+=/home/MYDOMAINCOMPANY/

After save, you need to restart some services:

sudo systemctl restart apparmor.service snapd.apparmor.service snapd.service snapd.socket

This should fix the issues with firefox.