PDF Watermarking - CAD

I can successfully setup pdf watermarking for documents.
But, It doesn't work properly for CAD. Therefore, I updated some editable two methods wm_SourceLookupTemplate and wm_SourceUpdateTemplate for CAD as well as create a Watermark Rule for CAD. It still doesn't work.PDF watermarked file doesn't come out, though Conversion Task was Succeeded. Is there anybody who knows that sort of issue?

Thanks Chit Hsu