As Dan said, the skin needs more work.
Original
this is my first model almost perfectly functions only face of the model that it does not show in the game. if somebody as I fix this I am thankful very!
My English Translation
This is my first model. Function-wise, it is almost perfect. The only problem is that one face (or triangle) isn't showing in game. If somebody can fix this, I will be very thankful.
To fix the face problem, reverse the vertex order, or as same programs say, face to front.