Diff'rent strokes, I suppose. I had to sit through an especially painful production about five years ago (and why they chose it is still a mystery to me).
But also from that error, and one I don't think anyone's mentioned yet:
Holly Golightly, musical of "Breakfast at Tiffany's", starring Mary Tyler Moore, with a book by Truman Capote. From what I've heard, beyond train wreck.
Also up there:
Mata Hari. I checked out the script at the Library of Performing Arts, and just reading it you could tell this was gonna close on page 6. Some of the stories about it are truly painful.
"That duck was a sexual toy, and it was on display!" -- an unknown Nashville town leader