Double&Triple check your layers.cfg paths and .rvmat files in \data folder. Notice that the lines are without the "P:\". I really don't have a clue what could cause that kind a error, just throwing suggestions :) I myself have discovered that always in the end the problem was in the paths... Of course you could also post your layers.cfg here. And make sure you have the MapLegend.png also in source folder and right path to it in .cfg.