BPC DM Package is failing with GETWA_NOT_ASSIGNED

We are facing an issue with DM package, this DM package is loading transactional data from BW info provider (BPC Consolidation model) to BPC Planning model using standard "/CPMB/LOAD_INFOPROVIDER" package. In this package we're using end routine for calling particular period data. but is giving dump as GETWA_NOT_ASSIGNED. In transformation file we given selections for all the dimension except time dimension , so for the same we are using end routine to filter data with current month (based on category dim member property). Before filtering import transaction data from buffer which is filled by SAP standard code. below are the sequence of steps which we found out. Before adding data to buffer using class - CL_UJD_PIPE_IO_BUFFER with method - IF_UJD_PIPE_BUFFER~BATCH_ADD, the class - CL_UJD_PIPE_SIMPLE_SOURCE and method - IF_UJD_PIPE_EXECUTE~BASAL_OUTPUT is called to get the input data which in turn calls the class CL_UJD_INFOPROV_READER method - READ_DATA in which the base FM 'RSDRI_INFOPROV_READ' is called. So the data itself is not being received by the standard FM 'RSDRI_INFOPROV_READ'. Hence the input data is not being added to buffer due to which the z-routine which is called, gets failed. attached ST22 dump.