El Capitan XQuartz fails to open. Abnormal code 126 I am running 10.11.2 on a Macbook Pro and have downloaded the Quartz 2.7.9 and installed it.  The installation GUI claims the XQuartz installation was successful.  I rebooted my machine and logged back in.  I attempted to start Quartz and there is a momentary activity on the docking bar, like the icon is going to appear, but then it does not. 

In the /var/system/log/system.log I see the following entry:

Jul 26 13:03:44 WAM-RMASA-01 com.apple.xpc.launchd[1] (org.macosforge.xquartz.X11.56032[3608]): Service exited with abnormal code: 126


I took a stab at installing a previous version of XQuartz 2.7.8 and that yielded the same results.

Any clues on what to look at to troubleshoot this further?  Looked for additional logs but nothing is popping out as being X11 related.

Not sure it is relevant, but I do not have Xcode installed.
I found that there was a hidden directory that contained extra logs.  The path is /private/var/log/system.log

Within this log I found additional information.Jul 26 16:38:55 WAM-RMAES-01 org.macosforge.xquartz.startx[44581]: waiting for X server to begin accepting connections 

Jul 26 16:39:11 --- last message repeated 8 times ---
Jul 26 16:39:11 WAM-RMASA-01 org.macosforge.xquartz.X11.stub[44680]: Xquartz: bootstrap_look_up(): Unknown service name
Jul 26 16:39:12 WAM-RMASA-01 org.macosforge.xquartz.startx[44581]: waiting for X server to begin accepting connections 
Jul 26 16:39:12 WAM-RMASA-01 org.macosforge.xquartz.startx[44581]: /opt/X11/bin/xinit: giving up
Jul 26 16:39:12 WAM-RMASA-01 org.macosforge.xquartz.startx[44581]: /opt/X11/bin/xinit: unable to connect to X server: Operation timed out
Jul 26 16:39:12 WAM-RMASA-01 org.macosforge.xquartz.startx[44581]: waiting for X server to begin accepting connections /opt/X11/bin/xinit: server error
Jul 26 16:39:12 WAM-RMASA-01 org.macosforge.xquartz.startx[44581]: waiting for X server to begin accepting connections 
Jul 26 16:39:12 WAM-RMASA-01 com.apple.xpc.launchd[1] (org.macosforge.xquartz.startx[44581]): FairPlay decryption failed on binary.
Jul 26 16:39:12 WAM-RMASA-01 org.macosforge.xquartz.startx[44736]: expr: syntax error
Jul 26 16:39:12 --- last message repeated 1 time ---
Jul 26 16:39:12 WAM-RMASA-01 org.macosforge.xquartz.startx[44736]: xauth:  file /Users/rmaes/.serverauth.44737 does not exist
Jul 26 16:39:12 WAM-RMASA-01 org.macosforge.xquartz.X11.stub[44835]: Xquartz: Unable to locate waiting server: org.macosforge.xquartz.X11
Jul 26 16:39:12 WAM-RMASA-01 org.macosforge.xquartz.X11.stub[44843]: Xquartz: Starting X server: /Applications/Utilities/XQuartz.app/Contents/MacOS/X11 --listenonly
Jul 26 16:39:12 WAM-RMASA-01 org.macosforge.xquartz.startx[44736]: /Applications/Utilities/XQuartz.app/Contents/MacOS/X11: line 12: /usr/local/bin/tcsh: No such file or directory
Jul 26 16:39:12 WAM-RMASA-01 org.macosforge.xquartz.startx[44736]: /Applications/Utilities/XQuartz.app/Contents/MacOS/X11: line 12: exec: /usr/local/bin/tcsh: cannot execute: No such file or directory
Jul 26 16:39:14 WAM-RMASA-01 org.macosforge.xquartz.startx[44736]:


These logs reveal possible reasons for the failure to start.  One is that the tcsh shell that is declared as my default shell came over from my linux account apparently.  TCSH doesn't exist on the same path that was defined by default. 

So for better or worse, I don't want to mess with the config in case IT has some clever link between what I change in my MAC profile and what my linux environment has, so I just make the following soft link.

sudo ln -s /bin/tcsh tcsh


A Bang!  XQuartz starts right up!