Irrlicht Engine

someone could explain me what i did or didnt do to have those errors :

this what appear in my console

Unknow data object in x file: KeyValuePair

Unknow data object in frame in x file: ObjectMatrixComment
Unknow data object in frame in x file: AnimTicksPerSecond

Unknow Joint refernced in x file: Bone01
Unknow Joint refernced in x file: Bone02

CXAnimationPlayer: Animationtrack without corresponding joint found: Bone01
CXAnimationPlayer: Animationtrack without corresponding joint found: Bone02

Loaded mesh: media/rotate.X

jointname0 = Box01
jointname1 = Bone01
jointname1 = Bone02