When I run apper from the console there is this: > apper.lib: errorCode: PackageKit::Transaction::ErrorNotAuthorized "Failed to > obtain authentication." > apper.lib: PackageKit::Transaction::ExitFailed > PackageKit::Transaction::RoleInstallPackages > kf.kwidgetsaddons: Invalid pixmap specified.
The problems means when installing packages apt-get needs to be used. Something is broken there. I thought it used to happen because of unattended-upgrades which is not even installed anymore. Let me know if I should try or check something.