(one) doesn't have a problem with that

That is not an issue or problem for one; one does not disagree with that. A: "We insist on interest being paid on the initial amount, given the considerable delay." B: "We don't have a problem with that." A: "Can I borrow the car? I promise I'll have it back before 9 o'clock, and I'll make sure the tank is full." B: "Sure, I don't have a problem with that." If you need to finalize everything in 30 days, the seller doesn't have a problem with that—he's an investor looking to move on from this property.