fsroot tree is invalid after Mojave install

Hey, I had the same issue on my Late 2012 MBP and this worked:

1. Start up Mac in single-user mode by restarting then press and hold Command + S.
2. Type /sbin/fsck -fy into the command line and press Enter. This will initiate a file system check. You will see the same error, however in this case the repair will continue and fix the issue.
3. Type reboot and press Enter.
4. Login as normal and run First Aid on Disk and the error should be gone.

Hope this helps.

I had this problem too after I upgraded to Mojave. I noticed Time Machine was no longer backing up and displaying the error "An error occurred while copying files. The problem may be temporary. If the problem persists, use Disk Utility to repair the backup disk". Running First Aid on the external USB back up drive indicated no errors. Running First Aid on the MacBook Pro SSD I was getting the same error: btn: invalid btn_btree... error.

I tried running Disk Utility First Aid in recovery mode and using the fsck_apfs command with various parameters (also in recovering mode) but it would keep displaying the same error and not fix it. I called Apple support a number of times and they weren't able to offer a solution to fix the problem (tried reinstalling Mac OS and other things).

But, I did fix it, by doing the following.

What I used:

- 8GB USB thumb drive

- external USB HDD of greater than or equal capacity of the MacBook Pro SSD

- a lot of patience

Process:

- Created a bootable USB of Mac OS Mojave install image (HOWTO here) with a USB thumb drive

- Booted Mac from USB thumb drive with Mojave install and with external USB HDD connected

- Installed Mac OS Mojave to the external USB HDD

- At the last stage of the Mac OS install, used the migration wizard to migrate all my data to the Mac OS install on the external drive

- Booted from external USB HDD to make sure it was working and had my data

- Shutdown, disconnected external drive, and booted from USB thumb drive again

- Erased the Macintosh HD (SSD in MacBook) with disk utility and reformatted with journaled file system

- Installed Mac OS to MacBook Pro (internal SSD)

- Then ran data migration wizard again on this install to migrate data from external USB HDD back to the MacBook Pro internal SDD

- Run First Aid on the internal SSD again, and there where no errors

- Time Machine backup works again!

I do find it hard to believe that First Aid was unable to fix the btree error in the first place however, and I had to go through this whole process to get Mac OS working properly again.

My 2015 iMac is having constant kernel panics since Mojave install. Disk Utility says "fsroot tree is invalid". Only solution I have found is to format drive and restore from backup - something I sure don't want to do! I'm calling Apple Tech Support this weekend. What a mess.

Same issue here on Mojave 10.14 with a MacBook Air (13-inch, Early 2014) and an encrypted hard drive. Ran Disk Utility and received the following message:

Checking the fsroot tree.

error: btn: invalid btn_btree.bt_key_count (expected 4123650, actual 4123708)

fsroot tree is invalid.

I booted into Recovery Mode (Command+R on start-up) and it would only allow me to run First Aid on the boot disc, and not the main hard drive. There are no other options, so this suggested resolution does not work!

Aside from formatting my drive and reinstalling everything, is there any other solution? Terminal?

Thanks!

Go back into recovery mode. Click on the "ghosted" MacHD and click the "Mount" icon. Your MacBook Air will ask you for your password to unlock your HD. Once you've done that, you HD Icon will appear as normal and you can then run Repair Disk. This will run the deferred repair necessary to fix the invalid btn_btree count. Once you've finished running this repair in recovery mode, reboot your MacBook Air and run Disk Utility again. You'll see the deferred repair command again and the invalid btn_btree count will be gone.

Hey, same issue here, but recovery mode didn't help, I did the following:

1) Boot to recovery mode (CMD +R when it chimes at boot),

2) I select the disk utility from the 4 options shown..

3) mount the drive (it's encrypted)

4) try to repair.

It shows the same as when normally booted, it doesn't get repaired, I tried running on the terminal

with fsck_hfs -fy /dev/disk1s2

and the same ...

I'm finding no normal issues during OSX usage, *but*, I found this when trying to resize my volume, to leave some space for a separate partition on the disk, I can't do it because of the hfs issues.

When you mounted the drive, what drive were you mounting? The Bootable Drive or the computer's HD?

If you did it mount the computer's HD, then it should have asked you for your password to mount the drive so you could run Disk Utility. Were you asked for your password?

I've just updated to Mojave 10.14.1 and am now having the same issues as mangelajo et al.

I have been through the exact process you set out for them, but unfortunately that hasn't worked either.

I still get the 'snapshot is invalid' and btree count errors after repairing the mounted HD in recovery mode's disk utility.

It doesn't get past snapshot 1 of 3.

What else have you got?

Same issue, Booting into Recovery and running First Aid doesn't help

Also, for me, the Mojave install was stuck, I had to manually Shut Down and continue once, I believe this caused the issue in the first place, or it might be a side effect, I don't know

All I know is error: btn: invalid btn_btree.bt_key_count (expected 9472147, actual 9472196) - and nothing repairs it

Booting into Recovery mode and running First Aid from there doesn't fix the "fsroot tree is invalid" issue. Neither does doing a Safe Boot and running First Aid. This has happened to me in the past after upgrading to High Sierra from Sierra. It was eventually fixed through an update Apple released about 6 months after High Sierra was released. I'm hoping Apple will release a similar fix eventually but hoping it'll be sooner this time around and won't take 6 months.

Also for me, running First Aid in Disk Utility via Recovery Mode doesn't fix it. I'm loosing more and more of my application icons, and some applications are really starting to act strange. I have the impression that more and more file system errors are on my APFS file system.

Same problem with my 2012 macbook pro after mojave install.

Could not get this to work either.

Spoke with apple support and went into apple store. No help either way. Just verified that my 512 ssd is good.

Told me to erase and reinstall but time machine backups might be corrupted too!!!

Horrible to release updates that make things worse!!

After trying several other suggestions this is the one that worked on my Macbook Pro 2017 with Mojave. Thank you!!! Go back into recovery mode. Click on the "ghosted" MacHD and click the "Mount" icon. Your MacBook Air will ask you for your password to unlock your HD. Once you've done that, you HD Icon will appear as normal and you can then run Repair Disk. This will run the deferred repair necessary to fix the invalid btn_btree count. Once you've finished running this repair in recovery mode, reboot your MacBook Air and run Disk Utility again. You'll see the deferred repair command again and the invalid btn_btree count will be gone.

Did it and less than 24 hours later spinning beachball of death is back and First Aid says that disk is corrupted again!

I have done this 3 times now and computer works fine for a while and then deteriorates.

Any suggestions??

Thanks