Had the same after upgrade from 16.04 to 18.04. According instructions at https://ubuntuforums.org/showthread.php?t=2349320 installed ttf-mscorefonts-installer version 3.7 from https://packages.debian.org/fi/sid/all/ttf-mscorefonts-installer/download and now waiting if it helps.
Had the same after upgrade from 16.04 to 18.04. According instructions at https:/ /ubuntuforums. org/showthread. php?t=2349320 installed ttf-mscorefonts -installer version 3.7 from https:/ /packages. debian. org/fi/ sid/all/ ttf-mscorefonts -installer/ download and now waiting if it helps.