My Intel MacBook Pro 13" (2020) keeps shutting down after the Tahoe update.

There are older system extensions and background components that remained on the system long after their associated applications had been removed. 

These included elements left behind from VPN tools, virtual webcam and microphone utilities, WD Discovery components, and older Microsoft and browser updaters. 

Even though the apps were no longer installed, the system extensions and background daemons continued loading during startup. 

After the macOS update, they became incompatible and began triggering kernel panics.

To fix the issue, first checked the System Extensions, Kernel Extensions, and LaunchDaemons/LaunchAgents folders in the main Library directory. 

They are several items that clearly belonged to software no longer on the machine. 

After confirming they were not required, remove the outdated and orphaned components. Anyone doing this should take care to delete only items they are completely certain are no longer needed.

After the cleanup, restarted the Mac in Safe Mode. This allowed macOS to rebuild system caches and reindex Spotlight. 

Restarted normally, is the system already noticeably more stable ?

Then reset the NVRAM and SMC, since this is sometimes helpful after a major OS update on Intel models.

Once these steps were completed, all of the kernel panics disappeared. The system stopped rebooting unexpectedly ?  Spotlight and Safari/WebKit stabilized, and overall performance returned to normal ?  

In short, major macOS updates can expose compatibility problems with older system-level components installed by third-party applications. Even if those apps have been deleted, their system extensions or background utilities may still be present and may cause instability after an update. Removing these outdated items and allowing the system to rebuild its caches may resolve the issue completely.

➡️. If all this seems daunting and above your comfort level ? ⬅️

Then we have another suggest

Start Over from Scratch 

Heavy Handed  ? - Yes 

Effective ? - Yes 

You can spend hours or days hunting down all the bits and pieces of these softwares and never really get it all off the computer

For Apple Intel computers >>   Use Disk Utility to erase an Intel-based Mac followed by How to reinstall macOS

Always make a Time Machine Backup  before  proceeding 

Emphasis on User Account Only

If going this route - I suggest Not using Startup Assist to migrate everything back.

Just reinstall the needed applications as new

Two cents here after looking at the report very quickly

GPU / logic board instability (most likely)

The symptom (partial screen blackout >> forced shutdown) is classic for:

GPU kernel panic

T2 bridge crash

thermal runaway (CPU reaches 100°C+, system poweroff)

Your fans becoming very loud right before shutdown also points to this.

Software driver conflict (likely)

In particular:

FortiClient kexts are old (SDK 10.13 → extremely outdated)

ExpressVPN daemon is unsigned

OBS and Iriun load system camera extensions

macOS 26 may panic when old drivers touch the graphics subsystem.

I shall step away with this >>

If the user believes these current issues stem specifically from macOS 26 Tahoe.

For a thorough test to determine if Tahoe is the root cause of all the computer issues.

Use the “Atomic” option >>>

Apple Intel computers >>   Use Disk Utility to erase an Intel-based Mac followed by How to reinstall macOS

Always make a Time Machine backup before proceeding.

Run the computer without installing any additional software and without restoring from your Time Machine backups.

Run the computer in this mode for approximately 6 to 8 hours and report back if the previous issues reoccurs.

See if the problem is present when you boot in safe mode, which disables 3rd party extensions and performs some system cleanup.

Start up your Mac in safe mode - Apple Support

itsdipu wrote:

Hence your suggestion to start the device in safe mode and leave it there for a while (?)

Correct. If you go several hours without issue, reboot normally. Sometimes that fixes issues. If not, the issue is likely a 3rd party extension conflict. Next step would be to run EtreCheck.

Please post an EtreCheck report. The app was written by a long-time forum member. The free version is fine. It doesn't change anything on your Mac, just reports on what's installed and some other system info, nothing private. Post the full report using the Additional Text feature of the forum (3rd button from the right in the formatting toolbar below the post box).

https://etrecheck.com/en/index.html

Thank you for the update re: actions you have taken to date

Perhaps 🤞 it may not be required to erase and reinstall Tahoe

Give it maybe another day and hopefully the machine will remain stable

If not and before venturing into an earse and installation

Perhaps another new Etrecheck report would be in order ?

Just make sure all the Bits and Pieces of OBS, Iriun, ExpressVPN, and FortiClients. are fully removed

We as in both myself and my colleague see the report

Will get back you once having done another analysis

You are very welcome

I for one, really hope the " doctoral exam is in two weeks " go well for you 🤞

Onto the business at hand

Purchasing a new Apple computer that you will own is a sound decision.

Before making a purchase, consider your current needs and project them forward three to four years. It is common for current needs to grow over time, such as the need for Unified RAM for video or image manipulation and the corresponding storage requirements.

The stock M4 MacBook Air comes with 16 GB of Unified RAM and a 256 GB SSD drive capacity. While this may seem ideal, the 256 GB drive is often insufficient for storage needs. Users frequently complain that the system data volume is taking up too much space.

Ultimately, make a customized purchase where an upfront cost may prove beneficial.

Time Machine Backup Utility is a preferred method for transferring content to a new computer. However, there is a caveat to consider. One size does not fit all in all circumstances.

The new MacBook Air will be an Apple Silicon computer, so it is recommended to only migrate the user account and nothing more.

Some users have had success with this approach, typically seasoned professionals who are well-versed in troubleshooting.

However, others have experienced issues when migrating everything.

Problems that existed on the older computer will be migrated to the new computer, potentially corrupting the new, pristine installation of the new operating system.

Applications, extensions and software drivers may not function properly on the new computer.

It is advisable to install new applications directly from the developer or the Apple App Store.

Conduct thorough research on new applications to ensure they are Tahoe compatible and consider the ARM processor of the Apple Silicon computer.

For further information, please refer to:

https://eclecticlight.co/2024/11/15/should-you-migrate-to-your-new-mac-and-when/