Unfortunately we cannot directly help as the volunteers here are not the same as Tech Support. As small business owners who have hands on experience with Square's Apps and Hardware, we do not have access to user Accounts. Just guessing that you may not included a subdomain as one of your app's domains however, we don't have all the details as to what changes you made or need to. You may want to contact Tech Support direct (can be done thru your Square Account) as they can look at your settings.
