I kept getting the Error Message “Failure to download extra data files with ttf-mscorefonts-installer on Ubuntu 16.04". This message would pop up about once a day and if I clicked on the "run this action now" button it would open a terminal window and do nothing. To fix this you goto Debian and download the ttf-mscorefonts and install them through the .deb file.Get the Debian MS-Core Font Installer Here.
The short and simple of it, download the linked file and double click on it then choose Install once the software center opens up. From what I've read this may be an error in Ubuntu and this is a work around.