URGENT, what's wrong with my TUI
 

Dear all, when I type ''//define/models/species/save-gradients?:yes'' into to my fluent TUI, I just got message ''invalid command [species]''........
What's wrong with my fluent 6.3?
Or is it a wrong way to set the rpvars?
I use a 2d version in this case.
And is there any other ways to set fulent to record mass fraction gradient in Pressure based model?

Thanks a lot !

regards,
HJ Wang