I recently noticed this too (in this forum, where you can also embed models).
https://3dwarehouse.sketchup.com/compiled.js?2a9b9bb line 1013: Error: Permission denied to access property 'page'
https://3dwarehouse.sketchup.com/embed.html?mid=u87c85b18-65de-41b5-b4d2-b6960f13eefe&width=400&height=300