Known errors and problems : How to resolve them

Fatal server error:
(EE) Cannot establish any listening sockets - Make sure an X server isn't already running(EE) 

To correct this Fatal server error, connect to the server who run job, then type following command : sudo htop

If htop is not installed, just type : sudo apt-get install htop.

Then, press F3 key and type : "xvfb". If Search find something press F9 and select SIGTERM.

Check another time if there's no more xvfb phantom process.

Problem should now be solved.

Fatal server error:
(EE) Server is already active for display 1
	If this server is no longer running, remove /tmp/.X1-lock
	and start again.

To correct this Fatal server error, connect to sthe erver who run job, then type following command : sudo rm /tmp/.X1-lock

Problem should now be solved.