Tips:   

FDMEE data load mapping validation fails when all the mapping  are correct. 


If you get FDMEE data load validation during data load when all the mapping are correct, like below error message in the FDMEE process detail Logs:

RuntimeError: [u"Error: Data rows with unmapped dimensions exist for Period '30NOV2016'"]

Cause:   If the system has duplicate mapping rows for any dimension, then validation would fail with the below error message in the process details.

Error message:
File "<string>", line 1788, in updateTDATASEG_T_TDATASEGW
SQLException: java.sql.SQLException: ORA-01427: single-row subquery returns more than one row.

Error message:

RuntimeError: [u"Error: Data rows with unmapped dimensions exist for Period '30NOV2016'"]

Then the problem could be duplicate rows are present in the member mapping. 

Looks for duplicate rows from data load mapping 

Delete the duplicate mapping row and re-execute the data load rule.