I’ m trying to upload a video ts file and it shows an error message
Are you using a Mac or PC? When this happens on my Mac it ends up being a permissions/privileges problem, when I’m trying to upload from a volume other than my boot drive. I copy the TS folder to my desk top and then can successfully upload with Cyberduck.
It may be a disk space issue. You can view how much free space is on the AppleTV it iTunes.