Re: Herald Achievement not unlocking PC

Just an update to close this question:

I never could get the particular game I was playing to flag the Herald achievement so I started another one. I played on nightmare and managed to slog my way through a bare bones playthrough that wasn't pretty to watch but worked. I received the Herald and Inquisitor achievements with no problem so I now have them all.

It's not a solution to the problem but I'll mark it as one to close the question. Thanks to all those who replied!