[OS X TeX] [MacTeX 2015] Cannot open Ghostscript for piped input

[Luis Sequeira]

You don't have permission to access or run gs for some reason. 
Either the directory /usr/local/bin has the permissions wrong, or more likely gs itself.

Type or copy/paste the following in Terminal:

 sudo ls -l /usr/local/bin/gs

Here is what I get:

 lrwxr-xr-x  1 root  wheel  23 Oct  1 11:36 /usr/local/bin/gs -> /usr/local/bin/gs-noX11

If you see something different instead of  lrwxr-xr-x that means the permissions are wrong.
You can fix them by typing:

 sudo chmod 755 /usr/local/bin/gs

If not then check the permissions of gs-noX11 the same way.
It should look like

-rwxrwxr-x  1 root  wheel  33016768 May  4  2015 /usr/local/bin/gs-noX11