The choppy playback on timeline occurs mostly by the files with high bitrate. Most files coming directly from a HD camera or Drone have a high bitrate, such as MOV and MTS files. But generally the output video quality will not be affected. As alternative, you can try to transcode the imported videos to .MP4 before loading to our program. The whole re-encoding process will help you reduce the high bitrate and keep the video quality.
After you save your work, it will be saved as an editable project (.wsfproj) file, which records all the edit information within your project, but does not store any imported media files. Instead, the .wsfproj file references that media. Therefore, if you move, delete, or rename any of the media files and try to open the .wsfproj, it will be unable to locate that media associated with the project. That is why you receive the error. Currently the only work around is to reload the missing file(s) to the project again manually.
To avoid the problem, it is suggested to keep all the media that are associated with the project staying where they belong to be originally.
Generally this problem occurs because the codec of the media that you need to import is not fully compatible with Filmora scrn. Since Filmora scrn works perfectly with .MP4. So you can download a free converter, such as Wondershare Video converter Free or Handbrake to do the re-encoding before loading to our program.