Time Machine completed a verification of your backups. To improve reliability, Time Machine must create a new backup for you.

I erased my time capsule completely on April 14, with zeroing out. So far (April 27) I have not had the problem. It's too early to say if the problem has been completely solved, that has to wait a few months. But encouraging so far.

An update: While I'd hardly call this conclusive, I've not seen this problem occur again since I disabled PowerNap on my MacBook Pro (Retina, 15-inch, Mid 2014) on April 6, 2017. So, yes, it's only been a month, but that's the longest reprieve I've seen from this error since it first happened to me in January of this year.

If the issue was as simple as disabling Power Nap on the Mac, Apple would have provided this "fix" long ago.

Glad that is working for you, but it does not work on the two Mac laptops here that have Power NAP disabled. One Mac went 4-5 weeks before the "verification" message appeared, the other a bit longer, maybe 6 weeks.

Hopefully, your Mac will go longer before the message appears again. I think it is more a question of "when" not "if".

Please post back in 60-90 days to let us know how things are working.

ahostmadsen wrote:

I erased my time capsule completely on April 14, with zeroing out. So far (April 27) I have not had the problem. It's too early to say if the problem has been completely solved, that has to wait a few months. But encouraging so far.

Sigh. Now I get a new type of error:

Time Machine couldn’t complete the backup to “Anders's AirPort Time Capsule”.

An error occurred while copying files. The problem may be temporary. If the problem persists, use Disk Utility to repair your backup disk.

Restarted computer and Time Capsule. Problem persists.

Hey gang--

Way back early in this thread, I too had the dreaded "must create a new backup" error. At the time I was running OS X Mavericks.

So, I just upgraded my iMac this week to El Capitan. I have not yet resumed Time Machine backups, and leaning toward erasing my Time Capsule and starting a new backup in hopes of avoiding future problems.

Just curious if anyone thinks that is unnecessary, good idea, other?

Thanks!

Dave

Expect the same issue with El Capitan no matter whether you try to continue existing backups or erase the Time Capsule and start over again with new backups.

The only question is when.....not if....the dreaded message will appear.

Ok, it has been two months now since I have last had this error message.

What I did was to turn OFF WiFi on my iMac so that my Mac is connecting to the TimeCapsule via ethernet ONLY.

This is the way I had always run it without problems ( for years ) I had only turned on WiFi when Sierra came out so that I could unlock my iMac with my Apple Watch.

I hate to be pessimistic, but this is probably as much related to the problem as turning the lights on and off. I never had a Wifi connection to TC and still got the problem. This is a bug in Time Machine that Apple is apparently unable/unwilling to solve

I also have this issue. On my MacBook and my fathers MacBook both running Sierra.

We use two NAS, FreeNAS and Rockstor.

This would indicate that its an issue with Sierra itself rather than Time Capsule or other NAS products.

You can speed up Time Machine by using typing this into Terminal:

sudo sysctl debug.lowpri_throttle_enabled=0

That will disable throttling until you reboot and makes Time Machine run faster, it will use more battery though. It's a good way to speed up a large Time Machine backup, especially when you have to create a new one.

The problem seems to have been quietly fixed, for Sierra anyway. I haven't seen a failure in what must have been months now, and I did not change anything new. This did happen to me very rarely before Sierra, and I wouldn't be surprised if that continued, but the daily/weekly failures seem to be gone.

I hope its fixed now, here's my experience anyway:

I had this problem after installing Merlin firmware on a Asus RT-AC56U router.

The asus has a time machine option --after a few days it would fail verification.

I then returned to using my time machine on my old airport extreme and that started failing verification also (this had never happened before)

Next I tried qnap NAS time machine, it started failing verification.

The common piece of hardware was my MacBook was still using wifi through the asus router to reach all of these.

I flashed Advanced Tomato firmware on the Asus and have been running for 5 months without a verification error, and can backup to anything (Asus router, airport extreme, Qnap)

Right now it looks like my problem was a wifi router problem, specifically something in the merlin firmware. I never ran the stock asus firmware long enough to test it.

I love the Merlin firmware so I tried switching back to it and immediately (on first backup) started having backup failed and would not even finish.

Switched back to tomato and no problems.

Not sure if other people are using a different wifi router or not but something to look into.

I switched mine because I wanted an AC router.

--This same message and problem occurs about once every 6-12 months for me. Each time, Apple Time machine says my Time Machine data is not usable, and gives me no option to rebuild the old data file, gives no error message to help track down the problem, and demands the backups start over from scratch, dropping all access to the old backups.

--It is a black eye for Apple that the Time Machine system appears to use a fault intolerant data file, provides no way to recover from whatever the problem is, gives no error messages to trace down the source of the problem, and has let this situation exist since at least 2012.

--Apple backup system is not for professional applications, and in a way is worse than no backup since it gives a false implication that I have a backup that I can rely on.

I note all the people playing with wild ideas that it is related to some software or hardware in their system. Well, maybe it is, but I suspect they are being mislead and do not see the depth of the problem with Apple Time Machine. In my case, with crashes occur once over 6-12 months, over a 4 year period, through a variety of Apple OS updates, how am I supposed to track down the problem?

--Why no error report when we are talking about the loss of a terabyte of data?

--Why no recovery scheme? Why toss out a terabyte of data without any effort to let the user recover and debug the problem?

--Why can just one error destroy an entire terabyte of data? Data file was fine yesterday, today one unknown error occurred and the entire file is gone. A file of this size and importance should be bulletproof and recoverable from a multitude of errors, at least in part.

That Apple has not addressed this angers me and makes me roll my eyes at those that say Apple systems "just work." How oblivious they are.

-->In a professional world, repeated failures of this magnitude would never be forgiven.

As you can surmise, the problem is arising again and I am at a loss as to what to do about it.

That Apple has not addressed this angers me and makes me roll my eyes at those that say Apple systems "just work." How oblivious they are.

-->In a professional world, repeated failures of this magnitude would never be forgiven.

I feel your pain. They are losing the plot, methinks. I tried to delete an old backup file off a portable disc the other day.... complete nightmare.

I hardly come to these support communities now. They used to be well laid out, easy and logical to navigate.... now the "too cool to breathe" presentation makes the place an unwelcoming pile of doo-doo. Mr Cook should focus on making Apple "just work" instead of promoting his unpopular politics.

Same issue here, using a Time Capsule. Took about a month to complete the initial backup, and then got the message about making a new one. At this point I consider Time Machine to be a bonus if it were to happen to work, but would NEVER depend on it.