This seems like a user configuration bug in the xdg stack. You can fix it by running this command in a terminal:
xdg-mime default nautilus.desktop inode/directory
Either way, I'm sure Unity is not to blame for this situation. And, though you can fix the issue running the command above, we need to search around for the root cause for the change, and fix it.
This seems like a user configuration bug in the xdg stack. You can fix it by running this command in a terminal:
xdg-mime default nautilus.desktop inode/directory
Either way, I'm sure Unity is not to blame for this situation. And, though you can fix the issue running the command above, we need to search around for the root cause for the change, and fix it.