Often when using network attached storage (NAS) devices that are not official Apple Time Capsules errors seem to appear. Although I don’t have absolute concrete proof, a setting I found seems to have stopped the problem happening on my ReadyNAS. If you get a error like the one below then read on:
Try starting the time machine again with the power nap setting enabled which can be found in System Preferences > Power Options. Now simply tick power nap at the bottom. This feature allows your Mac to wake up slightly and not go to sleep straight away to finish time machine backups. This seems to stop the corruption happening.