Confusing "Hash" Message on my MacBook Air

[mraamohamed]

Got this tonight after open my MacBook Air, not sure what it means do I have an issue what utilities can I use to check my system for errors.

 

[Raz0rEdge]

What version of macOS is the MBA running? Was it freshly installed when you got it? If not, you will want to save any data that you have on there to an external drive first and then go into the recovery console by powering down the MBA and powering it back up while holding CMD+r.

Once in the recovery console, you should erase the current partition on the SSD and do a fresh install of the OS.

 

[pigoo3]

Got this tonight after open my MacBook Air, not sure what it means do I have an issue what utilities can I use to check my system for errors.

In case you were interested in what the term "Hash" means in terms of computing:

Hash Definition

The definition of Hash defined and explained in simple language.

techterms.com

Maybe knowing this could help you track down the issue (if interested).

As advised by Ashwin. Probably best to backup the valuable stuff...and do a fresh OS install.

Nick

 

[Raz0rEdge]

My very quick searches online seem to indicate that this issue happens after a system crash or something bad happening. It looks like macOS takes note of a sanity of the machine by creating a hash during installation or something saying that we're good. If things break and the hash comes back differently, then the sanity of the machine is compromised.

No-one has a clear idea what the cause is, but the fix is always a re-install to get a new set of hashes.

 

[MacInWin]

If it is running Monterey, the installation process creates a hash code for the files as they are installed, then creates from the hashes a "master" hash that is then compared with what Apple thinks the hash should be. If they match, then the installation is a success and the files are as expected. Each boot the hash of the boot system is again calculated and compared to the hash of the installation. If they match, that's fine. If they don't, you get that message to say that some file in the installation no longer matches what was installed and you should reinstall the OS again from a known good installer from Apple.

Basically, it is a security check at boot that ensures what you boot is what Apple installed. As was told, backup your data drive and reinstall the OS to correct the situation.

 

[mraamohamed]

OK thanks for all the help, I have not had any problems since this error occurred. If it happens again I will follow people steps here and do a fresh install. BTW yes I am on 12.3.1 Monterey.

Thanks
Abdulah