ZTE N9130: Video recorded, but doesn't show under Camera, Gallery or a Video player, though it can be seen under File manager
Hopefully I'm not too late. 

I had the same problem I had  been looking for my videos for months. After reading what Izzy replies to you, I realized I was searching the right folder but in the wrong area. 

Go to your file manager app icon, it should look like a folder. Once you open it, select phone which is to the immediate right of category. Now you should see a list of different folders. Click on camera and scroll all the way to the very bottom passed all the photos, you should begin to see a small purple triangle indicating videos. 

I hope that helps you out.