falha na instalacao ubuntu 15.04

[Antonio Carlos Santos Galvão]

ao tentar instalar o ubuntu 15.04, a instalação parou informando falha.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: ubiquity 2.21.2
ProcVersionSignature: Ubuntu 3.18.0-8.9-generic 3.18.1
Uname: Linux 3.18.0-8-generic x86_64
ApportVersion: 2.15.1-0ubuntu1
Architecture: amd64
CasperVersion: 1.347
Date: Thu Jan 8 18:42:01 2015
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity initrd=/casper/initrd.lz quiet splash -- locale=pt_BR keyboard-configuration/layoutcode?=br keyboard-configuration/modelcode?=abnt2
LiveMediaBuild: Ubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20150108)
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=pt_BR.UTF-8
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu Foundations Team Bug Bot (crichton)]

Exception during installation:
Jan 8 21:41:42 ubuntu /plugininstall.py: Traceback (most recent call last):
Jan 8 21:41:42 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 1765, in <module>
Jan 8 21:41:42 ubuntu /plugininstall.py: install.run()
Jan 8 21:41:42 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 78, in wrapper
Jan 8 21:41:42 ubuntu /plugininstall.py: func(self)
Jan 8 21:41:42 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 204, in run
Jan 8 21:41:42 ubuntu /plugininstall.py: self.configure_plugins()
Jan 8 21:41:42 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 570, in configure_plugins
Jan 8 21:41:42 ubuntu /plugininstall.py: self.run_plugin(plugin)
Jan 8 21:41:42 ubuntu /plugininstall.py: File "/usr/share/ubiquity/plugininstall.py", line 547, in run_plugin
Jan 8 21:41:42 ubuntu /plugininstall.py: "Plugin %s failed with code %s" % (plugin.NAME, ret))
Jan 8 21:41:42 ubuntu /plugininstall.py: ubiquity.install_misc.InstallStepError: Plugin console_setup failed with code 1
Jan 8 21:41:42 ubuntu /plugininstall.py: