ORA-19756
        corrupt block number block_number found in change tracking file
        - block_number: The block number of the change tracking file.
        Cause
        The specified block number was corrupt in the change tracking file.
        Action
        There will be other messages on the error stack that show details of the problem. There will also be a trace file that contains a complete dump of the corrupt block.
        
     
    
    
        ORA-19756
        corrupt block number string found in change tracking file
        
        
        Cause
        The specified block number is corrupt in the change tracking file.
        Action
        There will be other messages on the error stack that show details of the problem.  There will also be a trace file that contains a complete dump of the corrupt block.
        
     
    
    
        ORA-19756
        corrupt block number string found in change tracking file
        
        
        Cause
        The specified block number is corrupt in the change tracking file.
        Action
        There will be other messages on the error stack that show details of the problem.  There will also be a trace file that contains a complete dump of the corrupt block.