First off the bat, the issue has NOT been found with Firefox 64-bit and does not appear to be an issue with Chrome or Edge.
hardcoreVids.tv is written with a modern web framework (as you would expect) and it uses something called Session variables. Those are different to Cookies.
When using the web site and when you login, you'll have something called a Session. Some people call this `Local Storage`. This is a very efficient way of running a site and very secure using something called `data injection` which in English means that the platform makes an instant check when you do something. You would never notice this.
However, this Session is held in what Web People call a `container` and this has a Session ID. That's all good or should be except for our file security system, which externally checks that you can watch or play a video. Modern Web Browsers should keep this Session alive or active (Chrome does), but some older browsers (ummm...) create a new Session for a file check. Why should that matter ?
Unfortunately, if the browser does this and it's really a browser bug, this new Session (or Thread) will set you back to the default Guest User and this results in a security error saying that you don't own this video.
Most Tech companies are now deprecating 32-bit Apps and regardless of your use of hardcoreVids.tv, we suggest this is a good upgrade. However to update your Windows 10 from 32 to 64 bit pretty much means a re-install, but you'll have modern Apps across the board.