Time Machine Error 41 "Verifying Backup"

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Hallo,
ich habe im Internet nun einige Stunden gesucht aber noch nicht zu meinem Thema gefunden:

Ich nutze zur Time Machine-Sicherung eine Raspberry. Das funktioniert auch alles super. Seit der Umstellung auf 10.10.2 bekomme ich allerdings, wenn ich am Strom bin die Meldung, dass das Backup nicht überprüft werden kann, weil es Read-Only ist.
Hat jemand hierzu eine Idee???

Auszug aus der Konsole:

28.02.15 16:21:53,099 com.apple.backupd[5093]: Starting manual backup
28.02.15 16:21:53,104 com.apple.backupd[5093]: Destination TimeMachineHD could not be found (url: (null) destinationID: xxxxx)
28.02.15 16:21:53,136 com.apple.backupd[5093]: Backup failed with error 18: The backup disk could not be found.
28.02.15 16:21:53,141 com.apple.backupd[5093]: Starting manual backup
28.02.15 16:21:53,146 com.apple.backupd[5093]: Attempting to mount network destination URL: afp://Simon@TimeCapsule%20Pi._afpovertcp._tcp.local./Data
28.02.15 16:22:03,568 com.apple.backupd[5093]: Mounted network destination at mount point: /Volumes/Data using URL: afp://Simon@TimeCapsule%20Pi._afpovertcp._tcp.local./Data
28.02.15 16:22:48,592 com.apple.backupd[5093]: Disk image /Volumes/Data/Simons MacBook Pro.sparsebundle mounted at: /Volumes/TimeMachine
28.02.15 16:22:50,677 com.apple.backupd[5093]: Backing up to /dev/disk3s2: /Volumes/TimeMachine/Backups.backupdb
28.02.15 16:23:01,458 com.apple.backupd[5093]: Deep event scan at path:/Users/Shared/iPhoto/Diverse/Database/apdb reason:contains changes|must scan subdirs|fsevent|missed reservation|file event|
28.02.15 16:23:01,459 com.apple.backupd[5093]: Running event scan
28.02.15 16:23:05,995 com.apple.backupd[5093]: Finished scan
28.02.15 16:23:06,003 com.apple.backupd[5093]: Not using file event preflight for Macintosh HD
28.02.15 16:24:35,604 com.apple.backupd[5093]: Found 857 files (152.4 MB) needing backup
28.02.15 16:24:35,610 com.apple.backupd[5093]: 1.98 GB required (including padding), 169.45 GB available
28.02.15 16:26:50,214 com.apple.backupd[5093]: Copied 1360 items (152.7 MB) from volume Macintosh HD. Linked 10112.
28.02.15 16:27:53,661 com.apple.backupd[5093]: Created new backup: 2015-02-28-162753
28.02.15 16:27:55,622 com.apple.backupd[5093]: Starting post-backup thinning
28.02.15 16:27:55,623 com.apple.backupd[5093]: No post-backup thinning needed: no expired backups exist
28.02.15 16:27:56,995 com.apple.backupd[5093]: Backup completed successfully.
28.02.15 16:28:02,392 com.apple.backupd[5093]: Ejected Time Machine disk image: /Volumes/Data/Simons MacBook Pro.sparsebundle
28.02.15 16:28:02,792 com.apple.backupd[5093]: Ejected Time Machine network volume.
28.02.15 16:28:02,793 com.apple.backupd[5093]: Running automatic backup verification.
28.02.15 16:28:02,794 com.apple.backupd[5093]: Attempting to mount network destination URL: afp://Simon@TimeCapsule%20Pi._afpovertcp._tcp.local./Data
28.02.15 16:28:14,336 com.apple.backupd[5093]: Mounted network destination at mount point: /Volumes/Data using URL: afp://Simon@TimeCapsule%20Pi._afpovertcp._tcp.local./Data
28.02.15 16:28:14,337 com.apple.backupd[5093]: Error 41 verifying backups. The backup destination appears to be read-only or unreadable.