Trying to reinstall 15.04 after some problems with unity

[Robert Fissette]

Installation stopped. Not yet restarted. I hope I will not have lost everything.
Installation on old installation, no reformating of disk.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: ubiquity 2.20.0
ProcVersionSignature: Ubuntu 3.16.0-24.32-generic 3.16.4
Uname: Linux 3.16.0-24-generic x86_64
ApportVersion: 2.14.7-0ubuntu10
Architecture: amd64
CasperVersion: 1.346
Date: Fri May 15 17:36:20 2015
InstallCmdLine: file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash -- maybe-ubiquity
LiveMediaBuild: Ubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20141106)
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu Foundations Team Bug Bot (crichton)]

Exception during installation:
May 15 15:32:21 ubuntu /plugininstall.py: SystemError: E:Sub-process /usr/bin/dpkg returned an error code (1)
May 15 15:32:21 ubuntu /plugininstall.py:

[Brian Murray (brian-murray)]

You might want to switch to using the final version of Vivid instead of an Alpha image.