“TimeMachine” can only be used if it contains existing Time Machine backups for this Mac.

I am trying to back up my Mac Studio, which was backing up just fine until MacOS 26.2, to a Time Capsule. Several days ago, Time Machine kept saying that the password was wrong, but of course, it was not. So, partly in order to free up space, I deleted the old backup (and two other backups for no-longer-in-use machines). Now when I try to back up the Mac Studio, I get the message shown above.

New backups can only be made using the new APFS snapshot format. Time Capsule does not support APFS, so a new backup cannot be made on the Time Capsule. If there was still a backup from the old method on the drive, Time Machine could continue with that backup method.

Since you have a Mac Studio, just get an external drive and use that for the backups. No need to complicate things with a network backup.

And now that I posted this, I see MrHoffman provided the same information.

Barney-15E wrote:

New backups can only be made using the new APFS snapshot format.

APFS file system support is not a consideration for remote backups. Exactly one of the available NAS option for Time Machine supports AFPFS. One. All other available and supported options do not. And don’t need to support APFS.

New local Time Machine backups on Mac are using APFS, but new backups in a NAS are using the preferred local file system on the NAS, with the NAS with Time Machine server support located using mDNS, and accessed using SMB file share.

What file system is being shared via SMB services can be APFS on a Mac, or can be pretty much any other semi-modern file system.

Time Capsule does not support APFS,

Time Capsule supports only AFP file share and not SMB file shares, and it is AFP file share protocol that is being removed, and it is the deprecation of AFP that is the limit here.

Time Machine requires APFS file system for local backups now yes, but needs SMB and baseline POSIX file operations for remote storage and backups.

TL;DR: AFP and APFS are quite different, and the local and remote Time Machine backups requirements are different.

More context is needed. Where did that statement come from?

I get the same message when trying to back up mac studio that has previously been backing up. But that stopped woking, so, in order to start over, I deleted the previous backup (and other old backups for machine that are no longer in use). This is to a 3TB Apple Time Capsule, and it is successfully backing up an M4 MacBook Air.

AZsport115 wrote:

@MrHoffman I appreciate the NAS recommendations. Do you have any advice about what sort of security features or other options we should be looking for when selecting a NAS device?

For Time Machine support, you need a NAS with Time Machine server support.

For security, keep the NAS firmware current, consider carefully before enabling remote access into the NAS, and where feasible reduce what packages are installed to reduce the potential targets.

Beyond that, your choice of what else you might want the NAS to do, beyond storage. Ubiquiti offers a very nice basic 2-bay NAS focused on storage (and which can be used with one or two HDDs, and that akin to a Time Capsule), while Synology is far more comprehensive (even with their two-bay models) and can be configured for zillions of customizable options.

I’m using Synology NAS, though expect to deploy Ubiquiti NAS given its integration with Ubiquiti networking.

There’s a Youtube channel NAScompares that might be interesting.

I am trying to back up my Mac Studio, which was backing up just fine until MacOS 26.2, to a Time Capsule. Several days ago, Time Machine kept saying that the password was wrong, but of course, it was not. So, partly in order to free up space, I deleted the old backup (and two other backups for no-longer-in-use machines). Now when I try to back up the Mac Studio, I get the message shown above.

I was able to determine via 2 separate calls to Apple Support that the message "The next major version of macOS will no longer support Time Capsule disks for Time Machine backups." actually refers to macOS 26.x Tahoe in the context of new backups on newly formatted Time Capsules. Since macOS Tahoe users are seeing this message, they're understandably assuming that "the next major version of macOS" refers to macOS 27, for example, and not the current macOS 26.x Tahoe, and consequently believing there is a fixable technical error.

Devices which were backing up to Time Capsule under an older macOS, and then upgraded to macOS Tahoe 26.x, should continue to be able to backup to Time Capsule.

However, devices running macOS Tahoe 26.x cannot back up to a newly formatted / erased Time Capsule in any circumstance--even if that same device ,running the same version of macOS Tahoe 26.x, was successfully backing up to that same Time Capsule before that Time Capsule was formatted / erased! Thus, for any reader who is running macOS Tahoe 26.x and is receiving an error message that there is not enough space to back up their new device to Time Capsule, you must find a solution that does not involve formatting or erasing the Time Capsule.

I realize this is counterintuitive and frustrating, and I'm posting this information in hopes it might save somebody a few hours of futile troubleshooting.

@MrHoffman I appreciate the NAS recommendations. Do you have any advice about what sort of security features or other options we should be looking for when selecting a NAS device?

More context is needed. Where did that statement come from?

Unclear what you’re trying to do. Time Machine works fine with a properly configured NAS (I back up 5 Macs in the house to an NAS).

Any help here?

Back up your Mac with Time Machine - Apple Support

That's very helpful. Thank you!

There are a few reports of this; that macOS 26 is no longer allowing the creation of new Time Machine backups to Time Capsule. This presumably also blocking the creation of other backups to NAS boxes via AFP, too.

Existing backups will apparently continue to work until macOS 27, but I’d expect the AFP deprecation warnings to escalate.

macOS 26 is the end of AFP support.

Time Machine backup to NAS via SMB and mDNS works fine, as this Time Machine server replacement for Time Capsule and AFP has been available for ~seven years. Ubiquiti, Synology, UGREEN, TrueNAS, ZimaOS, a Mac running macOS 11 or later and local storage, various options supporting Time Machine server exist.

Some of the previous discussions, articles:

• Time Machine not backing up to network - Apple Community
• time machine backup to multiple macs on o… - Apple Community
• Backup disks you can use with Time Machine - Apple Support