ORA-12714 invalid national character set specified

Error: ORA-12714

ORA-12714  invalid national character set specified 

ORA-12714 invalid national character set specified  is very common error and related to database parameters and sessions parameters.


Cause 

Only UTF8 and AL16UTF16 are allowed to be used as the national character set. Check your NLS_NCHAR_CHARACTERSET which is set using:

select value from NLS_DATABASE_PARAMETERS where parameter = 'NLS_NCHAR_CHARACTERSET';

it should return UTF8 Or AL16UTF16

Action

Ensure that the specified national character set is valid

Please aware that at session level, some parameters could be different. If you want to be sure, compare the results of:

select * from nls_database_parameters;

with:

select * from nls_session_parameters;

Please find the below information:-    

Bug No :- 2834295 

Cause :-  declaring cursor for a function that returns a table of NVARCHAR2

 Affects below products :

Product (Component)	Oracle Server (Rdbms)
Range of versions believed to be affected	Versions BELOW 11.1
Versions confirmed as being affected	10.2.0.3 9.2.0.8 9.2.0.2
Platforms affected	Generic (all / most platforms affected)

Fixed:

The fix for 2834295 is first included in

11.1.0.6 (Base Release) 10.2.0.4 (Server Patch Set)

Please check for document number on oracle support :-  2834295.8