OK then I suppose my complaint is not about the link I provided, but rather, the hyperlinks this website provides.
So when I clear my browser cache and click on this link on the left:
My browser wants to go to this address (which doesn't work):
https://manual.3dgamestudio.net/
Now, if I had already browsed to the http site, the link will actually take me here instead (which works):
http://manual.3dgamestudio.net/
There are similar issues with the links on this site too. See the "Online Manual" link here:
https://3dgamestudio.net/english/gstudio/download.php