I created a Spark video and trimmed individual video files WITHIN Spark that I uploaded to my project. When I was the sole owner of the project my preview looked the way I intended, yet when I invited others to view the preview, those video clips reverted to the original video file and the parts of the video I'd cut were again viewable. Is there a reason this occurred? Is there a way to prevent this from happening? Would it be best to trim the video in another video editing program before uploading it to Spark?