can't run xconsole as non-root user

Can't say on which version of FreeBSD it stop working, it's ok on 7.3, but doen't work on 10.2 and 11.0. When I start it, it says "Couldn't open console" within it's window. When I start it as xconsole -file /dev/console, it shows a blank window, no messages. su within xterm doesn't help (same result), I need to run whole Xorg as root to make it work.