need help on windows movie maker!! please help :(

I have been making a video for about 3 days now and it was working fine but when i went on it today it just detto "Movie Maker can't open this project file.The file may not be compatable with windows live movie maker o be currupted" then says "Error 0xC00CEE2D" if te know what i could do to make it work please tell me, it has never done this before.

thankyou :) xx