To delete an existing CU, select it in the list and click the Delete button. You will be prompted to confirm that you want to delete the selected CU. Once deleted, a CU cannot be restored (but it can be recreated in a new CU). You can only delete one CU at a time.
A situation may occur where a user accesses a favorite that contains a CU not available in the new CU tables (it was not converted or was deleted for some reason). The favorite still contains the original CU and the user may still place it. CU referencing, however, can no longer work because the CU references the original CU blob rather than the new flat table reference library. To correct this issue, replace the CU in the favorite with one that exists in the CU library.
Additional information about problems with migrating CUs is available in the Migrate Data topic in the Migration Warnings box.