Movie maker file corrupted/not compatible

I tried making a movie twice and both times I'm getting the same error message.  The first time I had saved the movie on a couple of occasions, but then the program shut down.  After that I couldn't open the file anymore.  The second time, I tried making the movie again, and this time saved more often.  Again it does not let me re-open the file because it is either corrupted or not compatible.  I tried saving it to a usb and opening it on another computer only to get the same message. The error message is 0XC00CEE26. I need the movie for a graduation ceremony, and I still need to make another movie by next week, but I'm afraid to use movie maker again and get the same result.  What should I do?