Iphone 6 Videos can't be imported

Hello,

on my iphone 6 there are about 50 videos which I made myself. They can't be played and they can't be imported. The new Photo Software (in German it's called "Fotos") does list them but if you try to import it says there is a problem with the file format or the file name. Both of which I did not change in any way. I wouldn't know how. iTunes doesn't list them at all. That other software "Digitale Bilder", which is probably called "Digital Pictures" in English does list the Videos. As you can see here:

Is there anything I can do in order to save these videos?

Thanks a lot in advance!