Can I change a thumbnail on a video?

I don't understand why some of my videos have thumbnails/covers and some don't. They are all created the same way.

One more Rise user who very much wants this functionality!  I'm also surprised that it's not already available.  

My work-around for now (like a couple others above) is that I upload the video to my video editing software and trim the first 1/2 a second and then save as a MP4.  However, this is a cumbersome thing to have to do, especially when you have numerous videos in your course.  It also causes the video to sometimes start abruptly since the beginning is being trimmed.

Just adding my name to the list of people who need this functionality (in Rise):)

Would like to bump this. Very strange this basic function of a thumbnail is not available in Rise.  

Yep, I know Sean.  This has been a feature request that was made a long time ago.  Really unfortunate that I have to spend time doing a work-around to get an image rather than a black screen.  I had this issue today while creating a short course that had seven videos in which I had to export to my video editor and insert an image.  That took an extra half an hour or so of my time.

Just adding my name to the list of people who need this basic functionality, which you would expect from Rise by now ;)

I'm adding my name to the list of people who require this functionality

I'm also adding my name to the list of Rise users that want this functionality. Please add this to your roadmap.

Adding my request for this feature - would be a lot less work than trimming the videos in another program.  

please fix this issue...