With S3-style storage service (such as AWS S3 and Wasabi), it is possible to mark files for 'public' access, which allows for the file to be accessed via a publicly-reachable URL. These URLs can be shared via social media sites, including Facebook. Facebook does examine all URLs from a security perspective and Wasabi has received some reports from some customers indicating they get one of these Facebook error messages below.
Wasabi is working with Facebook to determine why they feel this error message is necessary when sharing URLs associated with files stored in Wasabi.
The general method to troubleshoot these problems are to use the Facebook sharing debug tool (https://developers.facebook.com/tools/debug/sharing/) and enter your URL. We would encourage you to use this tool to ensure that you isolate any issues that relate to your URL, including letting Facebook know about the issue and soliciting their help if needed.
As soon as we have an update from Facebook, we will post a note on this in our Knowledge Base. Until then, it is safe to share the URL anyway, as Facebook does allow you to do this when you see the error message.