make gif

Have Toolbox Version 6.0.2 (4602) and trying to use the Make GIF app. Have tried using both MOV and MP4 video files however no GIF file is created. Any help would be appreciated. Thanks

Specifically, I want to be able to limit the number of frames created. As the number of frames is reduced from the default, the maximum span across the video should increase. If no limit the number of frames is given, then as the span across the video is increased, the number of frames should...