Had the same problem yesterday when upgrading in that apt-get wanted to remove calibre and calibre-bin from Nate Muench's PPA at https://launchpad.net/~n-muench/+archive/ubuntu/ppa, but today I was able to install them again.
Perhaps a reboot would fix it?
Had the same problem yesterday when upgrading in that apt-get wanted to remove calibre and calibre-bin from Nate Muench's PPA at https:/ /launchpad. net/~n- muench/ +archive/ ubuntu/ ppa, but today I was able to install them again.
Perhaps a reboot would fix it?