VLC player cannot open files or directories out of "/home"

Snap packages are in containers which prevent them from "seeing" outside of those containers unless you give them permission.

For VLC, I'd recommend uninstalling the Snap package, and using the vanilla APT version:

sudo snap remove vlc

sudo apt update && sudo apt install vlc

Snap applications can't guarantee the access of directories/files outside of current user's $HOME. From zyga's post:

• The $HOME directory of the user must match /home/*. Other directories are not supported yet. In particular /home/subdir/user is also not supported.

• any installation where the user’s home is not available if they're not logged in, is not yet supported. This includes:

  • installations using automount
  • ecryptfs and similar tech that unencrypt the $HOME directory (or partition) only while the user is logged in

Note here “not supported” does not mean “doesn’t work”. Some things might not work, but also some sequences of events might result in a user not being able to access their data.

So, it's better to switch to deb version of VLC provided by Ubuntu's official repositories. To install VLC, run

sudo apt install --no-install-recommends vlc

And remove VLC's snap package using

sudo snap remove vlc

Access can be given with snap connect:

snap connect some-snap-name:removable-media

The name removable-media can be misleading, but that how it works.