Failed uppdate to macOS tahoe 26.0.1 hash error codes 2019 mbp 16 inch

Question

Failed uppdate to macOS tahoe 26.0.1 hash error codes 2019 mbp 16 inch

Hi, just got the following error message after several failed update attempts:

Last login: Sat Nov 1 00:06:43 on console

oscar@MacBook-Pro-som-tillhor-Oscar ~ % softwareupdate -a -i

Software Update Tool

Finding available software

Downloading macOS Tahoe 26.0.1

Downloading: 100.00%Attempting to quit apps: (

"com.apple.Safari.SafariQuickLookPreview",

"com.apple.Safari"

)

Waiting for user to quit any relevant apps

Failed to download & prepare update: Error Domain=SUOSUErrorDomain Code=201 "Kunde inte förbereda programuppdateringen. Försök igen." UserInfo={NSLocalizedRecoverySuggestion=Ett fel inträffade när de markerade uppdateringarna hämtades. Kontrollera internetanslutningen och försök igen., NSLocalizedDescription=Kunde inte förbereda programuppdateringen. Försök igen., NSUnderlyingError=0x600002d30420 {Error Domain=SUMacControllerError Code=7740 "[SUMacControllerErrorPrepareFailed=7740] Failed to perform Prepare operation: [MobileSoftwareUpdateErrorDomain(MSU):1048_1_com.apple.ParallelCompression:1]" UserInfo={NSLocalizedDescription=Kunde inte förbereda programuppdateringen. Försök igen., SUMacControllerErrorIndicationsMask=0, NSDebugDescription=[SUMacControllerErrorPrepareFailed=7740] Failed to perform Prepare operation: [MobileSoftwareUpdateErrorDomain(MSU):1048_1_com.apple.ParallelCompression:1], NSUnderlyingError=0x600002d307b0 {Error Domain=MobileSoftwareUpdateErrorDomain Code=1048 "ParallelPatchExtractPayload() 'main' returned 0xa5049000" UserInfo={NSLocalizedDescription=ParallelPatchExtractPayload() 'main' returned 0xa5049000, NSUnderlyingError=0x600002d304e0 {Error Domain=com.apple.ParallelCompression Code=1 "Error 0xa5049000

invalid output size/decoder error: block=37, inSize=4056728, outSize=-1, expectedOutSize=8388608

worker proc reported an error

Threads reported errors

ThreadPipelineDestroy

processStream

PCompressFilter

ParallelArchiveRead failed

aborting current receiving thread

aborting entry

Destroying state with non-empty in-flight queue

Archive extraction failed

Extraction failed" UserInfo=0x60000236e800 (not displayed)}}}}}}

oscar@MacBook-Pro-som-tillhor-Oscar ~ %

Its a 2019 16 inch MBP, its had several messages for the past couple of weeks "hash codes not matching", attmpted to reinstall the original os before the upgrade, didnt work, also no issues found when using the disc control. Any suggestions? The computer is really sluggish in general, compared to how it was when new, also the fans seem to never really kick in, especially compared to how it used to be...

Any suggestions?

MacBook Pro 16″, macOS 13.7

Posted on Oct 31, 2025 4:46 PM

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Answer 1

Top-ranking reply

HWTech

Community+ 2026

Level 9

71,084 points

Oct 31, 2025 8:41 PM in response to Pacta sunt servanda

Pacta sunt servanda wrote:

Its a 2019 16 inch MBP, its had several messages for the past couple of weeks "hash codes not matching",

Where did you see this error message about hash codes?

attmpted to reinstall the original os before the upgrade, didnt work, also no issues found when using the disc control. Any suggestions?

So the install process did manage to change the system somewhat since you are trying to reinstall the older version of macOS (would it be Sequoia)? If so, then you will likely need to perform a clean install which involves erasing the disk which destroys all data on that drive.

The computer is really sluggish in general, compared to how it was when new, also the fans seem to never really kick in, especially compared to how it used to be...

Any suggestions?

Are you saying this laptop was sluggish before you attempted to upgrade to Tahoe?

FYI, upgrading to a new major version of an OS will not solve performance issues or most other problems. If anything, a major OS upgrade will just cause more problems making it even harder to figure out the initial source of a problem. Installing minor OS update patches is Ok since they rarely introduce more problems & are intended to solve problems. Minor OS update patch version are like 15.6, 15.6.1, 15.7, and 15.7.1.

Do you have a good backup of your laptop?

I have a bad feeling about this laptop reporting hash code errors. I suspect the Logic Board is failing which unfortunately is very common for this particular model laptop.....MBPro 16" (2019).

Try running the Apple Diagnostics to see if any hardware issues are detected. A passing diagnostic result means nothing....the Mac can still have a hardware issue which the diagnostics did not detect. The diagnostics rarely detect issues even when they have been confirmed through other methods. However, a failing diagnostic usually indicates an actual hardware issue.

Edit: Forgot to include the instructions for accessing the Apple Diagnostics:

Use Apple Diagnostics to test your Mac - Apple Support

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Answer 2

leroydouglas

Level 10

200,706 points

Oct 31, 2025 5:36 PM in response to Pacta sunt servanda

Pacta sunt servanda wrote:

Hi, just got the following error message after several failed update attempts:

Last login: Sat Nov 1 00:06:43 on console

oscar@MacBook-Pro-som-tillhor-Oscar ~ % softwareupdate -a -i

And why not go through the Software Update via the >System Settings>General...(?) and compare your results.

if you are determined to try again using Terminal I would suggest copy and paste:

sudo softwareupdate -i -a -R

-i Install

-a All appropriate updates

-R Automatically restart (or shut down if required to complete installation)

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Answer 3

Oct 31, 2025 4:59 PM in response to Pacta sunt servanda

¿what is the date of your most recent backup, and by what method?

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