Display setting in lxbatch

I’m submitting some root jobs on lxbatch using batch system.
Some times by chance I get this massage about display and then the code doesn’t run.

" root: can’t figure out DISPLAY, set it manually
In case you run a remote ssh session, restart your ssh session with:
=========> ssh -Y "

As I don’t do ssh to lxbatch machins myself so not able to do " ssh -Y" , How can I solve this problem?
I assume I should set a variable in my script but I don’t know what it is.

Thanks .

It looks like you start root without option -b