I've had this problem for a while in Sony Vegas where sometimes I crash (I don't have the greatest computer, and sometimes my files are pretty big so it happens) and when I open my project back up, this happens (this is my preview screen, I recorded it with Action).

At first I thought that it was just a glitch and when I rendered it it would be fine and back to normal. This was not the case and it still showed this weird effect after I uploaded it to YouTube (it happened with another video).

Anyway, I have no idea how to fix this, and it's been happening for a while. Does anyone have any ideas? :/