Drill_Fab Artwork \ Gerber is Blank

Hi All

I'm generating the artfile \ Gerber for a single layer board. 

When I import the created art file to Allegro, All the gerber  films are displaying correct except the drill art work which is blank ( only outline is showing).

The details are given below.

Tool - 16.6 version.  

Gerber - 

Visible layers in drill artwork. ->  Board Geometry -> outline and Dimension

                                                     Manufacture -> NCDRILL_LEGEND, NCDRILL_FIGURE, PHOTOPLOT_OUTLINE, NCLEGEND1-1, NCLEGEND2-2.

Let me know if I'm missing anything.

PS: On Board file, the drill chart , drill location and dimensions are visible for DRILL_FAB Film.