[xubuntu] ttf-mscorefonts-installer won't run/work

I installed Xubuntu 64 bit, 16.04, with no probs. That was 9 days ago. Since then, I keep getting this message:

Failure to download extra data files

The following packages requested additional data downloads after package installation, but the data could not be downloaded or could not be processed.

ttf-mscorefonts-installer

The download will be attempted again later, or you can try the download again now. Ruing this command requires an active Inteet coection.

I have tried clicking on the box to run the action now, but it never installs. Any ideas?