to check errors check We05 or we02 they are same
in general i think that most of problem is relate to Dates if that your case check that you converted dates to internal format using conversion step i advice use like this function
CALL FUNCTION 'CONVERT_DATE_TO_INTERNAL'
EXPORTING
DATE_EXTERNAL = ZHEADER-BEDAT
IMPORTING
DATE_INTERNAL = MBEPOH-BEDAT.
Award points if helpful
