When you upgrade your system to a new release, it may be necessary to convert reports you defined in the earlier release before you can use them in the new release.
The system automatically converts each report the first time you execute it following the upgrade to the new release. If this conversion is unsuccessful, you can convert it manually. For more information, see Customizing.
When you convert a report, you merely adapt the report's technical structure so that it conforms to the new release. Frozen report data is deleted during the conversion. The system then reselects the report data when you execute the report in the new release.