Recently it happened so, that while I was trying to copy a video file from my Moto G 3rd Gen to my Ubuntu Linux box it showed an error :
Error getting file: -6: Not Supported
First I thought may be the video file was corrupted. But when I tried to run the video from mobile it was running perfectly fine. Then I started to trouble shoot what might be wrong. I did a quick google search which showed many people were facing similar issue but none have posted any solutions.
So, I tried to copy another file from phone to laptop and it was copied fine. So, the issue was with the particular video file. I looked at the video file format. It was a .mkv file. So to confirm that the problem was with the particular video format, I tried copying another .mp4 file and it was copied successfully.
To work around this issue, I simply renamed the video file extension to .mp4 and then copied to my laptop. Once copied I then renamed it back to .mkv. And it worked fine :)