Huawei video app not working

[Android Central Question]

I got quite new Huawei P20. But recently I discovered that my phone won't play anymore the videos I have recorded. When I hit the button "play" on my video, the screen goes black for a second and then it takes me back to the gallery. The Huawei video app doesn't open at all. If I want to open the app, same things happens - screen goes black for a second.

What to do?