I agree .mov is not the best option. It is, however, my only source file. I have uploaded .mp4 to that same menu option and it has worked correctly. I am using a theme so that does complicate things.
I have dl the entire filesystem from the server and searched all the files for any mention of the video name. But there is only one. an ssl-logs.
Using inspect element on the browser I see customize.php and a document named after my domain. But when viewing those files in the text after dl, it is not the same.
I guess my question should be more like. If I wanted to change the background using ftp through editing of a text file. What would be the code locations? For the stock load of wordpress.
