Changing the scene already set forth, in a very obvious, unbelievable sort of way. For example, I give the opening post. In my setting, I describe a morning day, with my character going to get coffee. And when you enter, it's suddenly night time, in a club? Uh, no, I described something else entirely. It's not suddenly night time. I set it up for us to meet at the cafe, not a club.

Small mistakes I can handle - I'm wearing a blue dress, you mention it being green, no problem. But when something this major is changed, I just get incredibly annoyed.