Apps Script gadget on custom domain shows "We're sorry, but we were unable to locate the page you requested."
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I have created own apps script gadget in the site and inserted it in a page. When I open the site at http://sites.google.com/a/mydomain.com/www/sms-zprava it works. When I use my custom domain http://www.mydomain/sms-zprava it doesn't. The error "We're sorry, but we were unable to locate the page you requested." is shown. The gadget uses UI API.