system call failed

[vegeta18]

I am using dolphin 3.5 trying to record a replay of a match in super smash bros brawl. I went to graphics and clicked dump frames. The format i chose was microsoft 1 so that it would convert to an avi and i could put the video on facebook. Problem is when i go to watch the video i get an error message saying system called failed. Anyone know how to fix this?