Why am I getting Oracle error PL$/$SQL: ORA$-00942$: table or view does not exist for this PL$/$SQL$,$ when I have already confirmed that the table exists?

Declare

rows$\_$inserted integer :$=0$;

Begin

LOOP

Begin

INSERT INTO employee$($employee$\_$id$,$ last$\_$name, department$\_$id$)$

VALUES$($emp$\_$id$\_$seq.NEXTVAL, concat$(\text{'}$EMPLNAME$\text{'},$to$\_$char$($rows$\_$inserted$)),123)$;

$--$

$--$Only increment counter when no duplicate exception

$--$

rows$\_$inserted :$=$ rows$\_$inserted $+1$;

Exception When DUP$\_$VAL$\_$ON$\_$INDEX Then Null;

End;

exit when rows$\_$inserted $=500$;

commit;

END LOOP;

End;