Does this happen with new threads too? A lot of pictures on older threads are often deleted or moved and no longer visible here. Based on some quick reading I've done though, it seemed Photobucket released an update around the end of June that prevented users from embedding images on other websites, so now all previous images just are broken links like the picture you showed.
Sadly I don't think there's much that can done if certain pictures are broken. If the original poster is still active you could try messaging them to see if they would update their images, though. Otherwise the problem seems to be on Photobucket's part.