Fix ORA-08104

While rebuilding index my toad session was hanged and I decided to kill session but it also hanged

SQL> alter index xxx.xxxxx rebuild online parallel 8;

To fix it I connected db with new sesssion and got object_id of mentioned index

 SQL> select object_id obj#, i.status from dba_indexes i, dba_objects o  
 where o.object_name=i.index_name and  
 i.index_name='LOYAL_RES_IDX1';

--Note flags

SQL> select flags from ind$ where obj#=356001; 

Using DBMS_REPAIR package clean index

SQL> declare  
 isclean boolean;  
 begin  
 isclean :=false;  
 while isclean=false loop  
 isclean := DBMS_REPAIR.ONLINE_INDEX_CLEAN  
 (dbms_repair.all_index_id,dbms_repair.lock_wait);  
 dbms_lock.sleep(10);  
 end loop;  
 end;  
 /  

--Note flags

 SQL> select flags from ind$ where obj#=356001; 

As you see it was decreased and normal