errors occuring while uploading the material by using LSMW-IDOC in CRM SYS

Dear Experts,

I am trying to upload the MATERIAL creation from the flat file by using the LSMW-IDOC methodwhile doing i am getting an error called "Error status 'A' calling validation service".

I have completed all the 12 steps succesfully , i am able to see the read data from flat file into the corresponding field in custom struture ,i am able to generate idocs when i see the display converted data their also i am able to see the data in their corresponding fields, but when i see the idoc status in bd87 idocs are generated with error status "51" and stating

"Error status 'A' calling validation service".

when i expand the idoc generated in that when i see the status records following errors have been displayed.

with satus 51

Error status 'A ' calling validation service

Validation error occurred: Module COM_PRODUCT_MAT_VALIDATE , BDoc type P

Error during recategorization of product ZMAT9999 ; Change not transferr

Parameters required to call function module COM_CATEGORY_READ are missin

with status 62

Direct call started

No filters , No conversion , No version change .

could you plz help me out how to resolve the errors.

//

V.Srinivas