One more possible solution for those that might find this post someday.........
I have a new installation with the same problem and none of the posted fixes for the mpuck media browser image issue in this forum have worked, including this one. Odly enoungh, I happened to discover a fix that did work for my situation - create a new manager user!. In my particular case, only the default admin manager user has this problem. I can create new manager users leaving everything at the default and they all work fine. I don’t know if it will work for others in this situation and it makes no sense to me, but as long as it works..
