This reason means that your content doesnāt comply with our Contributor Agreement. Content may be non-compliant due to watermarks, inappropriate or irrelevant keywords or image titles, or questionable, or defamatory content. Your file is also rejected as non-compliant if you receive a reminder to submit a model or property release, or resolve a problem with a release, and you resubmit the file without addressing the issue.
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I would look into either into property realease issue or keywords/image titles.