10.2 to 11.2 upgrade ORA-20011/ORA-12702

Question

ORA-20011/ORA-12702 error received post upgrade (in 11g) when running full database stats,
   stats worked in 10g. upgrade appeared successful, no errors.
database:
freshly upgraded from 10.2.0.3.0 => 
Oracle Database 11g Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
CORE    11.2.0.1.0      Production
TNS for Solaris: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production
server:
SunOS xxxxxx 5.10 Generic_Virtual sun4v sparc sun4v
64-bit sparcv9 kernel modules
SQL> exec dbms_stats.gather_database_stats;
BEGIN dbms_stats.gather_database_stats; END;
ERROR at line 1:
ORA-20011: Approximate NDV failed: ORA-12702: invalid NLS parameter string used in SQL function
ORA-06512: at "SYS.DBMS_STATS", line 20508
ORA-06512: at "SYS.DBMS_STATS", line 20993
ORA-06512: at "SYS.DBMS_STATS", line 21150
ORA-06512: at "SYS.DBMS_STATS", line 21109
ORA-06512: at line 1
SQL> exec dbms_stats.gather_database_stats_job_proc;
PL/SQL procedure successfully completed.
SQL> exec DBMS_STATS.GATHER_DATABASE_STATS (estimate_percent =>100, block_sample=>FALSE, method_opt=>'for all columns size auto', degree=>null, cascade=>true, no_invalidate=>false, options=>'GATHER STALE', gather_sys=>FALSE);
PL/SQL procedure successfully completed.
SQL> !env | grep NLS
NLS_LANG=american
NLS_DATE_FORMAT=YYYY/MM/DD HH24:MI:SS
SQL> select userenv('LANGUAGE') from dual;
USERENV('LANGUAGE')
AMERICAN_AMERICA.AL32UTF8
SQL> select * from v$nls_parameters where parameter like '%CHARACTERSET%';
PARAMETER
VALUE
NLS_CHARACTERSET
AL32UTF8
NLS_NCHAR_CHARACTERSET
AL16UTF16
any ideas, please? I haven't seen this elsewhere..

Answer 1

may be its due to version issue. you Source database is 10.2.0.3.0  and it should be 10.2.0.4.0
Prerequisite
1.  your source database must be atleast 10.2.0.4.0  or Patch set for 10.2.0.2.5 should be installed
2.  Time version must be >= 4
Regards
Sanchit Gupta