Volume Hash Mismatch?

The only fix I found that helps is to run “Sudo Purge” from the terminal but it’s only temporary the hash mismatch may present itself again

I am also experiencing this issue. Attempted to reinstall MacOS Monterey 12.1, the issue persists. It’s causing apps to crash, webpages to reload, system restarts, black screens, etc. Hope this issue gets addressed soon, as I need my computer for school.

Edit: I’m experiencing this issue on my new 14” M1 Pro MacBook Pro.

Well… that wasn’t it after all. It took a while but the message is back. Genius Bar recommended I wipe and reinstall without restoring any of my data just to narrow down whether it’s something in my user account… which I guess is my next step.

if that doesn’t work it must be hardware, right?

Yeah, I have tried basically everything that you have tried, including wipe and reinstall without data. Still got the same message. I am basically certain it's hardware related, though the Genius Bar ran all sorts of hardware tests and none failed. I ultimately traded the problematic laptop in and got a new one. Restored with same data, using same OS version, and never had the issue again.

I am having this same issue with my 27inch iMac. In my case I have erased and reinstalled the OS three times with the latest version and have added no additional apps or backup info. I've run diagnostics with no hardware issues found. Still getting this error message and a kernel panic error. Mostly happens in sleep mode but recently has randomly restarted while using Safari. Currently working with Apple support and now awaiting feedback from captured data submissions.

I know it’s a lot of time, cause I went through it.

if you find some time, you need a 512mb+ usb that can be erased, one reboot to change the boot settings then the memtest86 should would likely be throwing errors within 5 minutes.

Otherwise, please consider a reminder to post again here in 30-90 days with status.

Thank you for the update! I’m glad to hear that this can work for some people. A lot of the postings are from people who have tried this or something similar and failed.

Your experience validates this as a step suggested by Apple.

Though, it is a lot less trouble to perform a memtest86 before starting from nothing.

What I mean to say is if someone encounters a volume hash mismatch, they are should test for a memory issue first because no reformatting / clean install will fix that.

I’m curious if we’ll see new reports of VHM errors on late versions of Monterey on macs with otherwise healthy hardware.

I got the Hash Mismatch warning twice since I bought the last manufactured 27" IMAC In October 2020. Specs: 3.8GHz 8 core 17, added memory 128 GB 2133 MHZ DDR4, AMD Radeon Pro 5500 XT 8GB, and 2TB Apple solid state drive. (Cost Over $5000) Started out with BIG SUR then upgraded to the latest Latest Monterey OS. I don't think I started getting the Hash mismatch BS using Big Sur? I got the first mismatch alert about three months after adding xtra memory. It said to reinstall OS. I have Applecare so called tech to find out, they seemed basically baffled. The first solution they suggested (after all the basic normal stuff like resetting the PRAM, restarting , slowdown, etc, you know the routine) running disk first aid, they suggested running disk first aid from the Command R startup., it seemed be trouble free for a few weeks ater that and I had the following issues, Preview, Photos, and Mail all crashed or froze several times, the screen froze, over night crashes, mouse wouldnt work and, plenty of minor glitches and errors and crash reports saying I had a problem. Reported all crash reports in detail. Kept up with OS upgrades (reinstalled twice) and got the Hash Mismatch alert once again about a month ago. Upgraded and reinstalled OS again, and noticed some speed and overall performance improvements but still had some of the annoying problems, but so far, despite all the annoying problems, I have been able to recover and do restarts, shutdown, etc, and was able to continue to normal functioning with annoying glitches mentioned above still happening about every 4-5 days. Called applecare again and asked the tech for suggestions. They really didn't have much of an answer other than that I was covered and they would fix the problem if the unit totally fails. I've been a MAC user and semi techno nerd for over 20 years (and took programing the in the 1970s) and none of the seven desktops I have had since were problem free, I've had almost every problem imagineable and even ending up talking to senior software develop team members for solutions, so I was hoping this one might be better, didn't happen! At this point I have pretty much resolved (from previous nightmares) that as long as I have three external backups, Carbonite, and cloud backups that at least if I have a catastrophic failure I can save my stuff, and get a newer model someday and suspect Apple will never come up with a fix. After reading all the discussions posted about Hash mismatch, it seems that it appears that there may be so many technical issues with all the different models concerning this problem there may never be a solution or magic fix that prevents it from happening. I think most of us MAC users have some sort of loyalty and use them for various positive reasons but its sort of sad that this type of thing is rampant in any manufactured electrical or mechanical device that use chips and processors. Considering the technical aspects of computers its absolutely amazing that they even work at all. I was told by someone who was a senior official with Apple that with problems like the HashMstach that if they don't get enough complaints (and especially customer feedback) they will basically ignore the problem. Good luck.

One more FWIW - 2+ weeks after my last status report, things are still running without the mismatch error showing up. So I'm again of the mind that erasing the drive and doing a clean install of the OS has "fixed" the issue.

As a last ditch effort I did an erase and clean install, but I still got the hash error again. Days later my computer froze and I attempted to restart it and it’s completely bricked now. Won’t go past Apple logo. Can’t access local or web recovery. Can’t boot from a startup disk. I think I must have had a hardware failure.

I have encountered the same problem on my Mac Mini (2018) following Monterey 12.1 install. The machine has restarted spontaneously twice in the last few hours. The following are the beginnings of the diagnostic screen. Full details available on request from Apple Support. Then I got the ‘hash mismatch detected on volume disk1s5

macOS should be reinstalled on this volume’ message.

panic(cpu 8 caller
0xffffff8009db6ce9): Possible memory corruption:
pmap_pv_remove(0xffffff9568f56f00,0x10f45d000,0xf7944f, 0x8000000f7944f004,
0xffffffe101e9bbc4, 0xfffffe9e2bc552e8): null pv_list, priors: 1
@pmap_internal.h:903

Panicked task 0xffffff870b6156d0:
1 threads: pid 1212: mdworker_shared

Backtrace (CPU 8), panicked
thread: 0xffffff9a342b8aa0, Frame : Return Address

and

panic(cpu 0 caller
0xffffff8008e3ebf1):
IOSCSIPeripheralDeviceType00::setPowerState(0xffffff8bcea716c0 :
0xffffff800b22de0a, 3 -> 2) timed out after 102100 ms @IOServicePM.cpp:5524

Panicked task 0xffffff909aa33670:
229 threads: pid 0: kernel_task

Backtrace (CPU 0), panicked thread:
0xffffff8bcca14000, 

I started getting this error this morning on my 2018 Mac mini. (It had unexpectedly restarted over night) This machine has been stable as a rock for years.

The change from me has been that I’ve unplugged my black magic eGPU without waiting for it to fully disconnect.

I’ve had to do this because I have a new work laptop and I have to switch back-and-forth once a day.

Apple does not provide for a way to cleanly move between two machines.

Now I’m here and I have to say this thread makes me very concerned about my machine.

I gave up on my 2019 MacBook Pro (it was a company-issued laptop). Not sure if the standard package of crap that IT installs messed something up, but it began kernel panicking several times a week, and when I tried to reinstall macOS from recovery mode it failed.

So I turned it in and they gave me a 13'' M1 MBP to replace it. This thing is just crazy fast and this isn't even the M1 Pro/Max. Hopefully no more Volume Hash Mismatches....

This is seriously concerning, I know I’m going to lose my OS at this point.

I want to try and perform a disk backup beforehand. What’s the best way to get a machine in this state stable enough to pull data, even manually copying directories?

Right now, after the login screen, the OS starts to load then shows this notification. About 20 seconds later there is a whoosh sound that I’ve never heard from the Mac before, and it crashes to cold boot.

The only pause in this loop is at the login screen.

btw, the OS is updated as of yesterday, 12.2.1