Yup, that one did it for me. After installing sh*#¤ loads of packages manually.

God knows what all this does to the server :D

For anyone encountering the same issue, and for future reference:

I ran into this problem on an Ubuntu 24.04 server provisioned through Forge.

I was able to resolve it by loosening the AppArmor restrictions using the following commands:

sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0
sudo sysctl -w kernel.apparmor_restrict_unprivileged_unconfined=0