I've set domain.com
as one of my Facebook App domains. Facebook website login fails on one of its subdomains with this error message:
Given URL is not allowed by the Application configuration: One or more of the given URLs is not allowed by the App's settings. It must match the Website URL or Canvas URL, or the domain must be a subdomain of one of the App's domains.
It's clear that login should be possible from a subdomain of an app domain, what is required to make this happen?