Hey @snupsband, how did you solve this error? I'm actually running into the same error and I'm currently not sure how to solve this error. At the moment I'm thinking that the error is related to #10997. I have fixed that error by adding an quarkus.properties file to the conf folder. This file only contains quarkus.http.proxy.enable-forwarded-host=true. This fixes the hostname for me. But the UI is still blank. I think that this is related to #11108.

Could you please post your fix for this problem?:)

In my case the issue was with my NGINX configuration. I didn't see any documentation in the Quarkus setup for actually configuring NGINX. My relevant settings are:

    location /auth/ {
        proxy_set_header    Host               $host;
        proxy_set_header    X-Real-IP          $remote_addr;
        proxy_set_header    X-Forwarded-For    $proxy_add_x_forwarded_for;
        proxy_set_header    X-Forwarded-Host   $host;
        proxy_set_header    X-Forwarded-Server $host;
        proxy_set_header    X-Forwarded-Port   $server_port;
        proxy_set_header    X-Forwarded-Proto  $scheme;
        proxy_set_header    ssl-client-cert    $ssl_client_escaped_cert;
        proxy_connect_timeout   2s;
        proxy_pass http://localhost:8080/auth/;
        proxy_buffer_size          128k;
        proxy_buffers              4 256k;
        proxy_busy_buffers_size    256k;
    }

If you're running a reverse proxy in edge mode then this might help. Without some of these headers the Keycloak application doesn't seem to be able to set internal URLs correctly (i.e., it relies on these headers to tell it where it is, rather than strictly using the hostname arguments).

I had some of these headers set in Keycloak v15 but apparently some of them were missing after the upgrade to v17.