If you have a slideshow you created a while ago and you see a thumbnail message that says either “Collection not available” or “Object reference not set to an instance”, it means that an image you had in that slideshow was moved to another collection or deleted. Unfortunately, unless you kept a packaged version of the slideshow or a printout such as flashcards or print view, there is no way to know what image was there. If it is an eRes slideshow, we probably have the flashcards archived on our server. Since an upgrade to soaMDID in 2008, we have been able to tell if an image is used in a slideshow, so we do not move or delete images until we have replaced them in slideshows. We apologize if this creates problems with earlier slideshows.