The black square just means that the map tiles and icon didn't generate properly. Your flight was super low and you had a GSD of .3 cm/pixel which is super small. We only generate tiles down to about level 25 which is roughly .5 cm/pixel. Basically this map has more detail that we are currently supporting with the web tiles but the image actually turns out OK.
The level we support was probably designed around older aircraft flying at 10 meters. It looks like we need to update it for the newer and higher resolution aircraft that have narrower fields of view and smaller GSDs.
Thanks for letting us know. This is not something a lot of people do.