There can be three major causes of the video playback problem:

1. Video parameters: the currently selected video parameters are not compatible with what the camera firmware supports. This usually results in video recording not even being started, but for certain parameter combinations video can be recorded, but the end result is corrupted. Solution: try other video quality options. These statistics may help: https://www.dailyroads.com/voyager/stats.php

2. Video stabilization: it’s main purpose is to reduce shaking in videos, but on some devices it doesn’t work properly, resulting in corrupt videos. Solution: disable video stabilization in the app’s video settings.

3. File system: video files are not properly stored on the SD card, mainly due to a corrupt file system or slow SD card. Solution: re-format the SD card, or replace it with a higher class/speed.