Creating iOS app preview in iMovie but getting iTunes Connect Error I'm creating an app preview for an iOS app using Apple's instructions (record video using QuickTime, import into iMovie, File -> App Preview) yet I get the following error message when I attempt to upload the video:

"Your app video preview is in the wrong format. For more information, see the Developer Guide".

The video is Mpeg 4, 640x1136 etc. so this seems odd. Has anyone been able to upload a video in this way?
Here is a trick using just iMovie and Quicktime to get the right dimensions.


Use QuickTime to record a short clip from the size of the device you need
Use iMovie and insert that clip into a new "App Preview" project
Add your actual video after the short clip


Now, any clips that you export will be in the right dimensions. 

If you need to hide your short clip, you can shorten it to 0.1 seconds. Put a title over it and delete the text. Now your video starts with 0.1 seconds of a black screen.