When ever I try to go here: https://subeta.net/user_shops.php/mine/1264/history, I get an error page.
I use Firefox and Windows 10

Those are probably legacy shops which no longer function. Here is a guide New Shop Guides which gives more information

Thanks but it's my own shop not someone elses. And I've already transferred from old shop to new.

yes, I actually do that every day. I'll just deal with it, thanks for responding