Can't play videos on iPhone 6

I recently activated iCloud for my pictures on my iphone 6. Last weekend I recorded two videos (both were about 20 minutes long). It seems like I can't play them. It says that their length 0:00 and I know that isn't true. I have tried resetting my phone and I have tried to play them from my computer. Nothing of it works. When I play the video on my phone the classic loading wheel appears. Help would be highly appreciated!

Thanks in advance!