Yes the login screen runs as a different user so it can't access your private files until you make them world-readable.
What gets me about this bug is that the black rectangle has nicely rounded corners, like an app window or a zombie splash screen from some app. If you run 'xwininfo' and then click on the black area, what does it output? ** No longer affects: gnome-shell-extension-desktop-icons (Ubuntu) ** Summary changed: - [nvidia] Desktop icons desktop is black + Desktop is mostly covered by a black rectangle -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1970141 Title: Desktop is mostly covered by a black rectangle To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell/+bug/1970141/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs