Crash while Installing Ubuntu 11.10 64bit using Unetbootin

[Ahmed Hosny]

Did umount -l -r -f /media/cdrom before starting the installer,
and it crashed while trying to work on filesystems before files copy.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: ubiquity 2.8.7
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 1.23-0ubuntu3
Architecture: amd64
Date: Sat Oct 15 20:00:45 2011
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)

[Evan (ev)]

Oct 15 20:00:32 ubuntu install.py: assert os.path.exists(fs_size), "Missing filesystem.size."
Oct 15 20:00:32 ubuntu install.py: AssertionError: Missing filesystem.size.

The tool you've used to create the USB image of Ubuntu did not copy all the needed files for installation. You need /casper/filesystem.size on the USB disk for the installation to complete.