I keep getting "error state invalid" when i try to add location

I had this same problem, it was the result of my address auto filling the form. If I would type in one field and tab to the next it would auto fill in the rest of the info and it would only say Province and not State. And even if I typed something in, it would still be invalid. So, what I had to do was click in each form field individually (NOT tab) and fill in my information. Once I selected the United States as my country a state drop down menu would appear and then I could select my state, and the form would submit properly.