I am getting the following error: ORA-00600: internal error code, arguments: [ktsk_dba_to_hwm-1], , , , , , , 
It fails on statement
execute immediate 'alter table ACTION modify lob (MESSAGE) (shrink space)';
This job and this statement are currently running sucessfully on 17 other databases. Any Ideas on how to fix the probelm and what caused it in the first place.
The Shrink space is running OK on other tables in the same Database.