i'm new with game studio, i'm using A6 V6.20 for create a basic game, but until now i can't build any room, every time i tried to build a map this error messages appear


.....CRITICAL ERROR......
E02A : Unknown entity type



while in the manual file write if this error appear it probably because
"You've tried to load an entity that is neither a sprite, nor a map or terrain, nor a valid model."
How come??? i just put a large cube and applied a default texture that's it nothing else.

Please somebody help me