I was testing an icon theme and a widget theme, but I removed the pocillo-theme and arc-theme. When I reinstalled it, it was missing some icons as the Nemo icon is no icon. How can I reinstall a package or dependency that recovers these missing icons?
Sounds like a package or two has been removed accidentally
sudo apt install --reinstall budgie-desktop-environment ubuntu-budgie-desktop reboot --
This will reinstall all the default packages and hopefully the missing packages you have removed.