/usr/bin/kate:11:xcb_setup_vendor_end:xcb_setup_pixmap_formats:find_format_by_depth:xcb_image_native:xcb_image_shm_put

The Ubuntu Error Tracker has been receiving reports about a problem regarding kate. This problem was most recently seen with package version 4:15.12.3-0ubuntu2, the problem page at https://errors.ubuntu.com/problem/39d629078ebb13b98b6736f2528a41015e2707c0 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/.