i used the kit for some time, but i can’t find the point, why the background don’t clear. The MainWorld Scene shows perfect, but when i press “i” for inventory, it appears and after another press on “i” close the inventory, but on the left there is a little leftover from the inventory. (See picture at https://drive.google.com/open?id=0B9RD5jW8RHhURlI1MDVycDV1WVU)
The reason that is happening (I think for your case here) is that in your Game tab for when you play the game in Unity you have yours in “Free Aspect” which has no restrictions on what you see as in your screenshot. What you want to try is to change “Free Aspect” to “16:9” or a resolution you will find perfect for your project.
Let me know if that solves the issue and shoot another thread/email if you need help with anything else.