| ERROR | Corrupted space header for datafile string, block string |
| CAUSE | When reading the space header block to use Unused Block Optimization for the backup of the datafile, the space header block had corrupted information. |
| ACTION | The corrupt space header must be fixed before Unused Block Optimization can be used for this file. Note that you should fix the corruption in any case because it will affect the availability of the data in the file, beyond just taking backups. |