After install pkg install virtualbox-ose and following the Handbook (https://www.freebsd.org/doc/handbook/virtualization-host-virtualbox.html) everything was okay but after reboot when I try to run: [root@freeBSD ~]# virtualbox Qt WARNING: could not connect to display Qt FATAL: This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem. Available platform plugins are: bsdfb, minimal, offscreen, vnc, xcb. Abort trap (core dumped)
Do you have X started?
Looks like it would have been "you don't have $DISPLAY set", which is likely if the OP su(1)'ed root in a terminal in some X session. Or didn't start X. The code in Qt's xcb platform plugin that produces the `Qt WARNING:` message shown here, prints the display name it has -- either from command-line options or $DISPLAY -- as part of the error. You can see it's blank. Closing as no-feedback, and probably forgot-to-start-X.