When I use a UIActivityViewController to share a webpage, it succeeds if the page has a photo and audio player, but fails if the page has a youtube video instead. By “fails,” I mean that after I select Twitter from the UIActivityViewController, the composer appears for a moment while it looks up the URL to generate a preview, but then instead of displaying a page preview, the composer disappears. The UIActivityViewController completionHandler indicates error == nil and success == false.
What could cause that? Thank you.