First of all, I tried to search if that was a common bug, but I didn't find anything about it.
So, I have installed worldpeace's Retry System:
For some reason, when I hit the midpoint, the "Back Area Color" change color, there's a example.
Before taking the midpoint: http://prntscr.com/ncz170
After taking the midpoint: http://prntscr.com/ncz1j6
The "Back Area Color" come back to normal after dying, I tried in few levels, but the color still change.
I hope someone know how to fix this, Thank you in advance!
(I also want to apologize for my english)