SYS.I_MON_MODS_ALL$_OBJ) violated during gather stats in 12.1.0.2.0

stats gather fails with error  , its a published bug for 10g and fixed in 11.1 ,facing it in 12c

ORA-00001 SYS.I_MON_MODS_ALL$_OBJ Encountered when Gathering Statistics (Doc ID 1448200.1)

BEGIN dbms_stats.gather_schema_stats(ownname=>'<OWNER>',estimate_percent=>NULL,cascade=>TRUE,degree=>4,method_opt=>'FOR ALL INDEXED COLUMNS SIZE AUTO'); END;

*

ERROR at line 1:

ORA-00001: unique constraint (SYS.I_MON_MODS_ALL$_OBJ) violated

ORA-06512: at "SYS.DBMS_STATS", line 36196

ORA-06512: at line 1