This is a server problem. For an unknown reason the tiles of zoom 11 to 18 are transmitted using the content type "appication/octet-stream" instead of "image/png". If you open a tile from an affected layer in the web browser it will not be displayed as image. Just test the following URLs and you will see. http://mapserver.mapy.cz/1turist-m/11-1115-700 http://mapserver.mapy.cz/1turist-m/10-557-350 Usually a content type different to "image/..." indicates a download error. Therefore the map tiles are...
JAXBException at loading profile
There was a small problem with the error message. Later in the exception dialog it is shown correctly: " The map source of map Greece 18 00 is unknown to MOBAC" Your profile uses the map "MapQuest" - which does not exist anymore. You have to edit the XML file manually and replace MapQuest with a map source name that still exists.
Error message handling on profile loading improved.
Clean-up: USGS map sources (some removed, some updated)
Problem loading multilayer map source