Editeing a level - no entities and tiles.

I'd like to modify a map in FT BOS. I've followed the EDITOR_README.txt: extracted ALL the *.BOS files to the core dir but when i run level editor and want to add a new entity there is't any entity list which i can select from. The same is with the tiles. There are entities/tiles already placed no the map but i cant add a new just because there isn't any to choose!

PS.
I'm using official FT Tools.