Unable to download video from icloud
10.13.4; iMac Late 2014
iPhone video shot in 2014 (720p) saved in photos now cannot be played within photos "because it uses an unsupported format." Photos library is uploaded to iCloud. Videos show as saved (?) in iCloud.com but also will not play. I tried to download the video files from iCloud.com but nothing happens. When i try to export the video file from Photos i get errors "internet connection required" (i'm online) and then "export failed to create a file" due to "unknown error." I'm unable to locate the videos on my hard drive.
Do my videos exist in iCloud.com?
Why can't I download the files?