After an update to 11.0, automountd would not start:
# /etc/rc.d/automount start
Assertion failed: (path == '/'), function create_directory, file /usr/src/usr.sbin/autofs/common.c, line 136.
Abort trap (core dumped)
It was because of an unfortunate merge leftover from freebsd-update, /etc/auto_master's first line was "========".
It could say something a bit less intimidating.