Using Manually Created Thumbnails instead of Fall Back Thumbnail

Hi, I uploaded a video (mp4) and it failed to make an thumbnail for it. After reading through the threads I realize it is probably due to the version of imagemagick on my server. I can accept that. So I manually created thumbnails, and put them in the full size, thumbnails, and square_thumbnails folders with the correct file name taken from the video stored in the original folder. Yet, in all instances it still shows the fall back thumbnail. Is there something else I need to do to get it to show the thumbnails I created?

I found it. I had to make a database change. In the omeka_files table, I had to change the "has_derivative_image" from 0 to 1.