/usr/bin/update-notifier:11:_gtk_icon_cache_has_icons:theme_subdir_load:insert_theme:insert_theme:insert_theme

[errors.ubuntu.com bug bridge]

The Ubuntu Error Tracker has been receiving reports about a problem regarding update-notifier. This problem was most recently seen with package version 3.168.1, the problem page at https://errors.ubuntu.com/problem/0848b540af5c3709f15ab984f599b7421504798f contains more details, including versions of packages affected, stacktrace or traceback, and individual crash reports.
If you do not have access to the Ubuntu Error Tracker you can request it at http://forms.canonical.com/reports/.