Ah!!! Okay...good catch! Thanks!!
It's the comma in the file name. In file masks, the comma is a mask separator. If you want to use it literally, you have to double it:
-filemask="Underwriting_mmcisoedi16488000_Correspondence_CORR_20170504_Cotterman & Company,, Inc. A & M Real Estate,, LLC Red Conncection, LLC Cotterman & Cotterman,, Inc.______________C_Submission_M_mmcisoedi33388621_.pdf|*/"