Oracle Message PLS-00383 - type mismatch found at string inside an IN or NOT IN clause

ERRORtype mismatch found at string inside an IN or NOT IN clause
CAUSEIn a test for set membership such as X NOT IN (SELECT Y ... ), the expressions X and Y do not match in datatype, and it is unclear which implicit conversion is required to correct the mismatch.
ACTIONChange the expressions so that their datatypes match. You might want to use datatype conversion functions in the select list.