All Oracle Error CodesOracle DBA Forum

NNL-00014:

unknown data type "string"
Cause: The user issued a name server request which contained an unknown data type.
Action: It is possible that the server had no information on the type, but automatically fetched it in response to the failing request. Re-issue the failing request; if the server has in the meantime fetched the appropriate data type information, the error will go away. If the error persists, the data type is probably invalid.