/usr/bin/totem-video-thumbnailer:6:g_assertion_message:g_assertion_message_expr:_g_value_types_init:gobject_init:gobject_init_ctor

The Ubuntu Error Tracker has been receiving reports about a problem regarding totem. This problem was most recently seen with package version 3.22.0-2ubuntu2, the problem page at https://errors.ubuntu.com/problem/163daaa268bfb8be01086de6860371067f73c623 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/.