RA-02270: no matching unique or primary key for this column-list

Hi all

I've expdp and impdp schema DATA only using these parameter files

userid=system/ora98dba
schemas=ewsys
EXCLUDE=VIEW,MATERIALIZED VIEW,MATERIALIZED_VIEW_LOG
content=DATA_ONLY
DIRECTORY=DATA_PUMP_DIR
exclude=statistics
filesize=8GB
parallel=4
dumpfile=expdp_ewsysdata_RSCKLP%U_081913.dmp
logfile=expdp_ewsysdata_RSCKLP_081913.log

and impdping the DATA after the create empty schema application with this parameter file, but before i use to disable all the contraints then execute the impdp

userid=system/ora98dba
remap_schema=ewsys:ewsys_owner
content=data_only
DATA_OPTIONS=SKIP_CONSTRAINT_ERRORS
table_exists_action=append
DIRECTORY=DATA_PUMP_DIR