Problem
You are using script injection to inject GRAVITY into a page, but when the page loads, you don't see the GRAVITY control and there is a message in the browser console
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or there is a 404 response with "site.not.found" as the error key
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Solution
In most cases this problem is caused by missing site configuration in the Admin site.
I.e. GRAVITY is injected on a URL, but there is no corresponding site configured on our backed and there is no configuration available for that site.
All you have to do is configure this URL for one of the sites so that GRAVITY will load properly.