I’m planning to buy yearly membership to this website, because the photos look very pleasing, but I also would like to hear some opinions from people who have or had monthly or yearly memberships. Is here anyone who tried it? link
the question I was asking was what does “sg-video” mean?
The only “sg” I know is Stanley Gibbons and it can’t be that.
Regarding your issue, and assuming you are a paid-up subscriber, and have signed in, you can download somebody else’s video and try uploading that.
You can always delete it afterwards.
This will confirm whether there is a problem with the video format you are using.