nothing gets saved

the plugin looks like it’s working, because the options on a post settings page are there and on the live page a placeholder shows. But every option including the .mp4 disappears when the post is saved — so the selected video never displays and the placeholder is always centered instead of left aligned.

What has to happen to make the video selected show and the display preference active?

https://wordpress.org/plugins/swfput/