There seems to be a programming error in aptdaemon, the software that allows you to install/remove software and to perform other package management related tasks.

[Dave Hales]

Binary package hint: aptdaemon

I am using 11.04.
Was able to download programs earlier today.
Now I get this error message, every time.

ProblemType: Crash
DistroRelease: Ubuntu 11.04
Package: aptdaemon 0.41+bzr646-0ubuntu2
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
Annotation: Applying software changes failed
Architecture: amd64
Date: Sat Apr 30 20:41:41 2011
DesktopFile: /usr/share/aptdaemon/aptdaemon.desktop
ExecutablePath: /usr/sbin/aptd
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
PackageArchitecture: all
SourcePackage: aptdaemon
Title: <type 'exceptions.SystemError'>: E:I wasn't able to locate file for the ttf-mscorefonts-installer package. This might mean you need to manually fix this package.
TransactionDepends: [[], [], [], [], [], [], []]
TransactionErrorCode: error-unknown
TransactionKwargs: {}
TransactionLocale: en_US.UTF8
TransactionOutput:

TransactionPackages: [[dbus.String(u'compizconfig-settings-manager')], [], [], [], [], []]
TransactionRole: role-commit-packages
UpgradeStatus: No upgrade log present (probably fresh install)

[Dave Hales (davezigzag)]

Reinstalled apt deamon files and had no further problems.