Cropping video frame

Hello,

I am using iMovie on my iPad. I have cropped each individual frame. When I try to replay the video there is a message that shows that the video is too high-quality for it to play.

I also noticed that on the tutorial for iMovie, there seem to be more editing tools available than I can see on my iPad, is there an updated version of iMovie I should be using?

Any help is greatly appreciated, thank you!