If it freezes, after rebooting, use journalctl to view logs from the previous boot before shutdown:

journalctl -p 0..3 -b 1

-p 0..3 is a filter based on the priority of log entries,
-b is a range of downloads,
-b 0 will show only logs for the current download
-b 1 for the previous one
-b 0..9 for the last ten