I am running the WIndows 10 Ubuntu and have installed the VcXsrv, "xhost local:root" broke it. This was a bad bit of advice I followed trying to get google-chrome-stable to work (it didn't).
Now VcXsrv seems to not be my X server anymore, no X apps work and I don't know how to undo the damage. Seems like xhost itself doesn't work anymore, tried "xhost -local:root" per the man page and it just goes off to nowhere. xhost -help does return the one-line help to the terminal window (which is the only thing working now).
Oddly the "XLaunch" VcXsrv "starter" works and will spawn xclock - but the terminal will not. So probably a problem on the Win10:Ubuntu side I am guessing. But now I'm out of guesses.