I spoke to several support people who couldn't help so I'm just trying to create a "paper trail".
I had exactly the same tax situation for many years but only this time it broke. The problem is that I live in NJ but work in NY. My employer gives me two W-2 forms where the second one, specifically for NY state, is almost empty except for boxes 15-17. Importantly, box 1 is empty. (Again, this is how it always was, and was never a problem.) As a result, the software "thinks" that NY state withheld more money (box 17) than I earned and treats it as an error that prevents e-filing.
It's a bug, plane and simple. If it is not addressed by the next tax season I will have to switch to another software or use an accountant.
