Inconsistency in Classification error in batch master

Hi,

i have three questions :

Q1) while changing a batch for a particualr material, ima etting the above error on MSC2n and MSC3n screen. the error appears after entering the material no and batch no.

the error is "inconsistency in classification data", transaction terminated. message no 12126

how to solve the above ??

Q2) can the material no and batch have different class type. for instance is it possible to give class type 001 for material in material master and for batches , the class type is 023 in batch master.

Q3) is it necessary to maitain classifcation data in batch master in MSC1N, if classifcation is defined in material master for the material for which we are creating a batch.

regards

sachin

can the material no and batch no have different class type. For is