Anybody interface ADT with Proficient Health?

I’ve had this interface up for a few months and every once in a while I get several ACK’s that contain this useless warning:

MSA|AE||An Error Occurred Processing Message.

Proficient Health asks me to resend the messages so I pull them from SMAT and shoot ’em across and they all come back with:

MSA|AA||Message Processed OK.

I would think identical messages should have identical results.

This vendor provides no specs (I was given one sample message and four lines of instructions) and doesn’t log warning info on their side.

Has anyone had better experience with Proficient Health? Or is this just one company to keep on “My List”?