Cant save or export project

Hello!

I just got my 7plus and saw it had the iMovie app so I figured Id get it a try. Well I made a trailer but it wont let me save it to iCloud or just my camera roll. It also wont let me post it to Facebook, it just pops up with a blank post asking me to say something but there is no video in the post to be posted. Ive looked online for help but didnt help.

Also, if I share it to iMovie Theater, will other people see it or will I be the only one to see it?

Please help!

Kurama247 about iMovie, v2.2.3