Bad Transferring

I got iMovie a while ago and decided to edit a little montage of my family vacation. So I downloaded the clips and edit it. But I try to share it on YouTube and I edited it yesterday and its every time I try to upload it, it says "share failed" and its not my internet because I use hotspot and wifi. I hope someone fixes this or its a waste of money

xxunicornbaexx about iMovie, v2.2.3