deactivating OCSP did not solve the problem.
I assume, this means that the OCSP errors are gone by now, but the redirecting issue is still there.
Concerning whitelisted host names. Since I assume, you have a single server instance running, all requests will be routed to the single server. btw, the standard way to define multiple domain names is to list these in the ".../servers" section of the driver module (see example in https://naviserver.sourceforge.io/5.0/manual/files/admin-config.html#subsection6). The white-listed hostnames are an OpenACS alternative for this, which might be necessary in containerized setups and older versions of NaviServer, which anyhow should work always.
I am still wondering about your setup, which I do not know: Is it the case that you have a single server configuration in your NaviServer configuration file, and you use for this server two domain names "celtic-arts.org" and "www.celtic-arts.org". And, you have OpenACS 5.10.1 installed, and no host-node maps etc. configured. Right?
Since you have a redirect loop, which seems to come from the /register call, the problem is in "ad_redirect_for_registration" or in "security::get_register_subsite". That hints, that you have probably subsites configured. I think to remember that also subsites might have different registration URLs and policies, maybe there is something wrong on your site.
But still, the mystery for me is, that you said that you have only updated the certificate. You did not answer to my earlier question about SANs in the old and new certificate.
