It depends on the problem as to how you proceed to give notice, correct the issue, and then take more action. 

And by the way he said, the property may have an environmental problem as he had been dumping motor oil in the back area.

If so, then I think you have a real problem, as it likely it means it was evaluated to be possibly grandfathered and determined not to be legal.  

I had this problem a few years back when starting a commission only job.

Title Insurance will be the most restrictive).Your illegal duplex might have the same Title Insurance problem as this post:https://www.biggerpockets.com/forums/44/topics/441853-need-help-with-colorado-1972-subdivision-law...although that pertains to an unapproved subdivision of a 10-acre raw land parcel.Good luck.

He told me that plumbing companies are buying up water heaters by the hundreds as fast as manufacturers can produce them to have stock on hand and prolong dealing with this problem a little longer.I got quotes from three different independent plumbers and eventually decided to tackle it on my own. 

As Eddie mentioned, I ran barefoot for many years in real estate and never had a problem. As

I started my company because I had the very same problem as you did.  

That said, I just won't take the money up front and avoid the problem as you suggest.If I do the following things would that solve the issues you raise?

Should not be a problem, as they have to abide by real estate law.