Invalid MIT-MAGIC-COOKIE-1 key: cannot connect to X server :1.0 on CentOS 6

__error__
root@server:/home/admin
$ <file>
Invalid MIT-MAGIC-COOKIE-1 key<file>: cannot connect to X server :1.0

admin@server:/home/admin
$ su <file>
Invalid MIT-MAGIC-COOKIE-1 key<file>: cannot connect to X server :1.0

__fix__
the problem is associated with x window forwarding

I was in a vnc session initiated from user admin and the .run file I was trying to execute was not able to forward the window through the terminal to the vncserver I was using

root cause is still unknown

_workaround_
start a vnc session under root (not generally supported) and then execute the file

this correctly opened the GUI