This is bug #1679784, which was fixed in software-properties 0.96.20.7 in April 2017. You are installing from obsolete media; please use the latest point release of Ubuntu 16.04 for installation if you are going to install 16.04, since many bugs have been fixed since July of 2016.
This is bug #1679784, which was fixed in software-properties 0.96.20.7 in April 2017. You are installing from obsolete media; please use the latest point release of Ubuntu 16.04 for installation if you are going to install 16.04, since many bugs have been fixed since July of 2016.