Forgot to mention that after the new login the following files are present in
~/.cache/:
activityswitcher_wallpaper_preview.kcache
akonadi_ical_resource_0/
fontconfig/
gstreamer-1.0/
icon-cache.kcache
kio_http/
ksycoca5_de_MFTZsp59pBGb5QxQ8sLS1UtUuXo=
mozilla/
plasma-svgelements-openSUSEdefault_v0.9
plasma_theme_openSUSEdefault_v0.9.kcache
thumbnails/