I *think* it may have to do with the time or weather. I'm not certain, but if it's night try turning it to day or vice versa, or setting the weather to clear or something? I'm sorry if that doesn't help, I don't have my pc with the game so I can't test the theory myself
Oh, that's really sweet! But I just trade for fun, I don't need anything in compensation, especially not something as time consuming as a drawing. I really appreciate your kind offer, though!