ORA-14400 inserted partition key does not map to any partition

Alter table LDBO.POWEROFATTORNEYSTOCKS add PARTITION SAUDA_APR2019 values LESS THAN (TO_DATE('01-MAY-2019','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M );

 

 

Alter table LDBO.TBLSNPRISKDETAILS add PARTITION SAUDA_APR2019 values LESS THAN (TO_DATE('01-MAY-2019','DD-MON-YYYY'))  TABLESPACE USR STORAGE (INITIAL 100M NEXT 100M );