We tried to contact https://schema.org/Book.jsonld from JSONLD Strawberry Field Key Name Provider but we could not. HTTP with code 404 says: Client error: `GET https://schema.org/Book.jsonld` resulted in a `404 Not Found` response:
<html><head>
<meta http-equiv="content-type" content="text/html;charset=utf-8">
<title>404 Not Found</title>
</head>
<b (truncated...)
. Check that URL or try later again!
To start over, you must empty your existing database and copy default.settings.php over settings.php.
To upgrade an existing installation, proceed to the update script.