Removed the ATTVIBUG compile option.
If you do have the bug, then workaround it like described in the FAQ:
Subject: 06.01 What to do with "Problems with edit - draft removed".
From: John Romine <jromine at ics.uci.edu>
Date: Mon, 1 May 1995 00:00:00 -0800
If your users are using an AT&T version of "vi", it's exiting with
non-zero status (supposedly a count of the "errors" during the
edit). Move "vi" to "broken_vi" and put it its place :
#! /bin/sh
/usr/ucb/broken_vi "$@"
exit 0
Alternatively, compile MH with the ATTVIBUG option.
Then complain to your vendor that "vi" is broken, and they shouldfix it.
btw: ex-vi does not have this bug.