XDM authorization key matches an existing client

[John Nielsen]

On Oct 27, 2014, at 12:56 PM, Eivind Evensen <eivinde at terraplane.org> wrote:
> 
> Hello. On FreeBSD elg.hjerdalen.lokalnett 10.0-STABLE FreeBSD 10.0-STABLE,
> I have a problem running certain X programs.
> 
> They tell me:
> .milkytracker
> XDM authorization key matches an existing client!Couldn't initialize SDL:
> Couldn't open X11 display
> 
> 
> Using xhost +localhost works around the problem, but I'd rather not
> have to do that if avoidable.
> 
> I can't really see anything in the options for sdl that seems to
> have an impact. Does anybody have any ideas where I can start to look?

I had a similar (IIRC) problem recently. Try appending
  DisplayManager*authName: MIT-MAGIC-COOKIE-1
to /usr/local/lib/X11/xdm/xdm-config and restart xdm and your session. That disables the XDM-AUTHORIZATION-1 authentication which, in my case, solved the problem.

JN