Graphic adduser crashes on username having characters not allowed

[Daniel Jenkins]

On clean install. Getting to:

system configurations -> Users -> Add New User.

If the system user contains '.' (maybe even some others characters) the system reports and error but does not clarifies why in order to change the entry.

"running '/usr/sbin/adduser' failed: El proceso hijo terminó con el código 1"

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: adduser 3.113+nmu3ubuntu4
ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6
Uname: Linux 4.4.0-21-generic x86_64
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
CurrentDesktop: GNOME
Date: Mon Apr 25 23:25:35 2016
EcryptfsInUse: Yes
InstallationDate: Installed on 2016-04-23 (2 days ago)
InstallationMedia: Ubuntu-GNOME 16.04 LTS "Xenial Xerus" - Release amd64 (20160421)
PackageArchitecture: all
SourcePackage: adduser
UpgradeStatus: No upgrade log present (probably fresh install)

[Leo Arias (elopio)]

Hello Daniel. Thanks for reporting the bug.

Could you please add all the steps to reproduce it?

[Launchpad Janitor (janitor)]

[Expired for adduser (Ubuntu) because there has been no activity for 60 days.]