Wiki URL: umbranet.miraheze.org
Your custom domain: wiki.umbranet.mandelbrotgames.com
Do you want Let's Encrypt: Yes
Hello, it seems that you have not pointed your domain correctly to Miraheze's servers. Please make sure to read https://meta.miraheze.org/wiki/Custom_domains and let us know when you have pointed your domain to us.
Thank you. I have done so. Sorry for the mistake.