Advice that "Legacy system extension" blocked for Seagate next upgrade from Sequoia 15.5 MacOS

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Advice that "Legacy system extension" blocked for Seagate next upgrade from Sequoia 15.5 MacOS

I am getting very nervous about performing a future "upgrade" of my 2020 M1 MacAir following several warnings that I will not be able to mount my Seagate drive. Have turned off Auto updates. Apple and Seagate seem to be making it my responsibility for the situation. Yes, I have previously performed the Security & Privacy update to enable the kernel extension in order to complete the drive installation. The online Seagate "support" seems to refer to upgrades to OS12 and 13. No mention of the current OS15 situation. Can I assume the same? If not my drive does not mount!

Is this how Apple behaves forcing an upgrade to my well-performing 2020 MacAir?

MacBook Air (M1, 2020)

Posted on Oct 30, 2025 3:56 AM

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Answer 1

Top-ranking reply

John Galt

Level 10

154,648 points

Oct 30, 2025 5:15 AM in response to BruceFromDownUnder

External drives do not require any third party software. Uninstall whatever software you installed. To learn how to connect and use external storage devices on Macs please read Connect and use other storage devices with Mac - Apple Support.

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Answer 2

MartinR

Level 7

24,053 points

Oct 30, 2025 5:24 AM in response to BruceFromDownUnder

What Seagate drive is this? What app and/or extension is this?

Is this app/extension something like Samsung/Seagate SecretZone or Secure Manager? If you used Seagate's utilities to encrypt the drive you may not be able to remove the extension without losing your data. Don't uninstall anything until you have done full research to identify what you have.

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Answer 3

Oct 30, 2025 5:14 AM in response to BruceFromDownUnder

FWIW, there is absolutely no need for third party drivers for external drives. At best they are a waste of space at worse they can cause all manner of unexplained issues and even render drives useless.

Macs all have the necessary drivers built in to support USB or Thunderbolt based mass storage devices.

As far back as I can remember I have never installed manufacturer drivers for external drives and have never had any issues!

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