The new update is glitchy!

I use iMovie to make YouTube videos that I have yet to upload or for quirky & humorous trailers. Well, ever since I downloaded the new update, its been very obnoxiously glitchy. It messed up my recording placements in a video, caused a few clips to automatically mute, made one clip repeat a part of itself, & even caused that same video to be unplayable; it has the clips but if I try to play it, then it does nothing but have a black screen in place. I need to start over with my arrangements now!

Robotic Kitty about iMovie, v2.2.2