MDX fail error - SAP BW data source

[Cognosy]

Hi.
I am using Cognos 11.0.10, and receiving this error
First Report Error

XQE-GEN-0010 Found an internal error: 'XQERuntimeException':
XSB-ERR-0016 Execution of MDX failed:
XSB-ERR-0028 BAPI Error while executing Function BAPI_MDDATASET_SELECT_DATA:
Type=A,ID=BRAIN,Num=299,Msg=System error in program CL_RSR_HIERARCHY and form _MEM_UNAMS_TO_MEMBERS-01- - ABAP:

Second Report Error

XQE-GEN-0010 Found an internal error: 'XQERuntimeException':
XSB-ERR-0016 Execution of MDX failed:
XSB-ERR-0028 BAPI Error while executing Function BAPI_MDDATASET_SELECT_DATA:
Type=E,ID=BRAINOLAPAPI,Num=510,Msg=Value , 0MATERIAL__ZPRODCODE ZPRODUCTCATEGOR for characteristic 0MATERIAL__ZPRODCODE unknown - ABAP:
RSV-SRV-0042

The data source is SAP BW and reports are running fine in SAP BW. Other Cognos reports using same hierarchy and BW as data source are also running properly. What could be the reason and resolution for this.
Thank you for taking out your time to read through my issue.
AG