Thanks a lot Martin, I did as you suggested and now it seems the command is running, but I still get an error before it starts:

CellType required and not defined.
MetaObject: Read: MET_Read Failed
data has been relabeled: 0 --> group A = 0 ; 1 --> group B = 1
#A: 36, #B: 67
this version does not support writing out covariance ellipsoid stats
tupel: 3 , numFeatures: 3006
group sizes: 36/67 = 103
Features : 3006 , real: 1002
........

should I ignore the first two lines?! what does this mean?