I’m not sure exactly where the problem is, but I think one of the errors at least arises because you are using http:// instead of https:// for the website.
The other possibility is that there is a permissions problem somewhere the files/directories instructor, pgProblemEditor2 AP_Physics/Tutorial/2/ chain.
When I try to put that address into the browser I get to the login page and I’m blocked, but you should be able to put in a username and password
and get to that problem and edit it. See what happens.
The url $server_root_url in site.conf is probably correct in using http: (and that seems to be what your site in general is using) but something
is asking for a secure connection back to the server (i.e. https) and doesn’t handle gracefully the fact that your site uses http. Almost all
sites now use https for the added security. The simplest fix would be to add an https (port 443) input to your site. It’s even possible to
configure it so that requests addressed to http:… are automatically redirected to https:. That might fix it and in any case it’s a good thing to catch
up with current practice and use https.