/usr/sbin/smbd:6:dump_core:smb_panic_s3:smb_panic:cups_pcap_load_async:cups_cache_reload

The Ubuntu Error Tracker has been receiving reports about a problem regarding samba. This problem was most recently seen with package version 2:4.4.5+dfsg-2ubuntu5, the problem page at https://errors.ubuntu.com/problem/6c5aea3c5d644dc1f2a4a56f9c9ad24d68e20706 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/.