I have found what I believe were errors in the answers to a few quizzes. I submit a correction to the author and then never hear back. I was just wondering if there is a system in place to follow up on uncorrected errors.

What if the author has left or died? I'm sure that there are people who would be glad to research and correct possible errors who may not be qualified to be an editor.

Yes, there is a system. See this thread and this one.

I know that as an editor, I seldom reply to a player who has has sent a correction notice, when I am taking care of corrections for authors who have left. There is just not enough time - it is not unusual to have more than fifty corrections to take care of (I usually do it twice a week). Since I have to research all those which I do not have direct knowledge of, you can see this would take up a lot of time.
Unfortunately, we can't allow someone who is not an editor to do this, as there is a lot of judgement involved - it is very seldom just a case of correcting spelling or changing a date. When it IS a simple matter, I really want to do those myself, as a break from the tricky ones!