Email the problem to tech and commish as soon as you get this message. In the SUBJECT LINE, indicate something like "Bad Lineup in (league)"
In the text of your message be sure to indicate your league, your team as the home team, and the name of the visiting team.

In my experience, John or Mike gets on these quickly, sometimes within a couple of horus. They will reconstruct the other team's away lineups so the rest of the series should go without recurring problems.
Dave N