What version of the tool are you running?
It sounds like you need to set your bb via spacing to 0 mils. Historically a SMT pad was considered a bb/via and dropping a via in pad would cause this error. You could get around it by setting the minimum = 0. Try that and see if it works.
Also, post a JPG of the pad/via with DRC marker to help validate what's going on.
Change your BB Via Stagger Min to 0.0000 (see attachment). I changed one of my rows to 5.0000 and got the same error as you. I have to have via in pad (blind via or micro via).