Some platforms, such as WhatsApp, Facebook, Instagram, TikTok or YouTube, occasionally reject a 1SE mash because of its video codec. Exporting it again from a free video editor fixes this.
Download a free video editing app.
On iOS: iMovie
On Android: CapCut or Splice
Import your mashed 1SE video into the app.
Re-export the video at the same resolution as your mash. Upscaling to 4K adds no detail — it only makes the file bigger and slower to upload.
Upload the newly exported video to your desired social platform.
This fixes upload problems caused by the codec.
