"An error occurred during export"

I loved this app. Past tense - loved. It WAS easy to use and made high quality simple videos. However, when Im done and trying to export the video or upload to YouTube, I would get this error message. Ive tried solutions found online like shutting down app, restarting phone, adding a photo to the beginning but nothing works. Im going to have to look into other video editing programs...

Sekshiiiii about iMovie, v2.2.3