@Idy we noticed the 206 response too, and initially when we first received this warning, we would force ngnix to respond with a 200 to deliver the entire page on each crawl.

This initially solved the issue, but a few weeks later we again had the same error.

Checked: - Page always delivers 200 - All robots are allowed - no dead links in the page that could lead to an error - all best practices - Other businesses within our group use the exact same server setup and Privacy Policy layout, but have no issues

While debugging the response from Facebook when trying to resubmit a Privacy Policy URL gives us what seems to be an internal Facebook missing field table error.

No Facebook partner has been able to resolve or even understand the problem, and developer support is impossible to reach.

The business that is suffering from this cannot even create a new app to try and get Facebook functionality reestablished. Other companies in the group that I admin can, however..

This seems to be the purgatory of Facebook ... Nobody knows why we land here, and there's no way out...