Oracle Error EXP-00086: Primary key REFs in table “string”may not be valid on import

Oracle Error Message

EXP-00086: Primary key REFs in table “string”may not be valid on import

Reason for the Error

The specified table contains primary key REFs which may not be valid in the import database.

Solution

Do not use Export/Import to move Primary key REFs between databases having differing character sets.