Well, The maintainer will not look into it. I believe that there's something malformed or suboptimal on this package that causes this problem, and I believe that this problem may appear in other circumstances if not looked into and fixed.
To be fair, however, there's a workaround that works (so far): if you are using this package in a (bash) script, do redirect the output to a file or log, or use "tee" if you also need terminal output, otherwise it will fail and just stop. For example, this would work: update-pepperflashplugin-nonfree --install --verbose >> /var/log/apt/updatepepper.log 2>&1 Cheers, Jamil Said