file will not download

This appears to be a common problem based on a Search. I cannot find a working solution. I have spent 2 days & multiple browsers trying to add 15 minutes that was split and clipped off of a Digital conversion from a VHS I made. I am just trying to combine them into one video. Download has failed repeatedly. Nothing works. I can't understand why this problem is so common and there is no explanation, assistance or FAQ on your website anywhere as to why.