Comments

I just tried checking it and it seems you haven't made the file public yet.

But anyways if you're trying to embed a photo here, a nice alternative would be hosting the photo directly from here by uploading it on your Profile Photos.

Then open the photo to another tab and copy the link.

Then go to the Blogpost you're working on and click the Image Icon and Paste the link from there.

Same for Bulletin Posts and Comments as well 

That's how I do it