# chflags -R nouchg /Volumes/{Drive}/{Machine}.sparsebundle
(DiskUtilityで一旦マウント外す。)
# hdiutil attach -nomount -readwrite /Volumes/{Drive}/{Machine}.sparsebundle
/dev/disk3 GUID_partition_scheme 
/dev/disk3s1 EFI 
/dev/disk3s2 Apple_HFS 
# fsck_hfs -rf /dev/disk3s2
(数時間)
# hdiutil detach /dev/disk3s2

その後
/Volumes/{Drive}/{Machine}.sparsebundle/com.apple.TimeMachine.MachineID.plist を編集
・<key>VerificationState</key><integer>2</integer> >>2を1に変更
・<key>RecoveryBackupDeclinedData</key>と<data></date>を削除。