Welcome to the ODK forum, @inasar751 ! We're glad you're here. When you get a chance, please introduce yourself on this forum thread. I'd also encourage you to add a picture as your avatar because it helps build community!
Please note that Aggregate is no longer being supported. Central is now the ODK server. The post below has for more details about the end-of-life for Aggregate.
Does the error message actually read mydomain.com or does it read with the URL of your server (and you are just keeping it private for this post)?