/usr/bin/kactivitymanagerd:11:QMetaObject::invokeMethod:Plugin::retrieve:StatsPlugin::currentActivity:ResourceScoreMaintainer::Private::run:QThreadPrivate::start

The Ubuntu Error Tracker has been receiving reports about a problem regarding kactivities-kf5. This problem was most recently seen with package version 5.18.0-0ubuntu1, the problem page at https://errors.ubuntu.com/problem/ec5671e4c8e8904647059dab179a4d2815fd30f6 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/.