Zone grid outside of drawing border missing

Afternoon all,

I have a quick questions regarding the zone markers within my drawing,

I cannot see the grid and need it at the moment for a drawing I am making revisions to, 

the drawing has around 20 revisions and the grid system would work great but I cant seem to find how to bring it back?

Thank you all in advance!

Dylan

SolidworksDrawings And Detailing