Comment 4 for bug 1551511

The warnings reported here, about user _apt and their privileges, are non-blocking and don't impact the successful download of the additional data. They have been reported in several other bug reports (e.g. bug 1658707), but not investigated yet.

Actual errors in the download of additional data have been solved recently for ttf-mscorefonts-installer (see bug 1607535) and pepperflashplugin-nonfree (that shouldn't be used anymore anyway, use adobe-flashplugin instead) (see bug 1632870). If you encounter such an error, update to the most recent version of the package and refer to these bug reports. Closing the bug as Fix Released.