I have an ArcMap 10.2.1 (Desktop) version. I added different layers from the catalog, that all are listed in the table of Contents now, but some of them are not visible in the data frame. I set spatial reference to all of them and also to the data frame. Some png. files and some jpg. files can not be shown while other files (also some png. and jpg.) don´t make any problems.
Many thanks for helping me!