When I last tried to update a Dell laptop, I got these errors. How can I fix this? E: /var/cache/apt/archives/mint-artwork-common_1.8.1.2_all.deb: subprocess dpkg-deb --control returned error exit status 2 W: Failed to fetch http://packages.linuxmint.com/pool/upstream/f/firefox/firefox_60.0.1+linuxmint1+rosa_amd64.deb 404 Not Found [IP: 68.235.39.11 80] W: Failed to fetch http://packages.linuxmint.com/pool/upstream/f/firefox/firefox-locale-en_60.0.1+linuxmint1+rosa_amd64.deb 404 Not Found [IP: 68.235.39.11 80]