1. Please format your microSD card first. See via https://support.viofo.com/support/solutions/articles/19000046583-how-to-format-the-microsd-card-
2. Download h2testw_1.4.zip at the bottom of this article.
3. Open h2testw, select your target and choose write+verify.
4. Waite until the test is finished and keep a screenshot.
It is important to choose a MicroSD card with good quality. We recommend choosing a microSD card with high endurance and UHS-U1/U3 or above class.
Bad-Quality microSD cards have short life endurance and may cause various problems when you use your dashcam. Most of the recording issues are caused by bad-quality microSD cards like randomly stop recording, video corrupted, etc.