ORA-20011

ORA-20011: Approximate NDV failed: ORA-00600: internal error code, arguments

Windows 2008 Enterprise
Oralce 11.2.0.2
After upgrade from 11.1.0.7 to 11.2.0.2 release, as part of R12 dbtier post-installation procedure, required to run adstats.sql and getting the following error

ERROR at line 1:
  ORA-20011: Approximate NDV failed: ORA-00600: internal error code, arguments:
  [1350], [1], [23], [], [], [], [], [], [], [], [], []
  ORA-06512: at "SYS.DBMS_STATS", line 24098
  ORA-06512: at "SYS.DBMS_STATS", line 24629
  ORA-06512: at line 3
  ORA-06512: at line 33

Finally found the cause of the error, environment variable ORA_NLS10 not set even though successfully completed the  $ORACLE_HOME/nls/data/old/cr9idata.pl executed to create $ORACLE_HOME/nls/data/9idata from upgrade notes

set ORA_NLS10=%ORACLE_HOME%\nls\data\9idata

Retest the issue by running adstats.sql again .

adstats.sql should run successfully now.