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Utz78's avatar
Utz78
Copper Contributor
Dec 09, 2025

MS Defender 101.25102 update error

I have been trying to update MS Defender for several days now and without luck. I am on a iMac M3 with macOS 26.1.

I tried removing and reinstalling the app, but it seems that the uninstall script does not remove the app at all. Yes, I did restart the machine.

Does anyone have a solution?

 

 

2 Replies

  • EddieC's avatar
    EddieC
    Copper Contributor
    Dec 12, 2025

    Yup - it has to do with tamper protection. Known issue on this version.

    You'd need to disable tamper protection and then the update goes through without issue. Then you an re-enable it: https://learn.microsoft.com/en-us/defender-endpoint/tamperprotection-macos#manual-configuration

  • rekluce's avatar
    rekluce
    Copper Contributor
    Dec 10, 2025

    This was an issue in our company. Upgrading from 2506X is a known issue. As far as I know, only your IT admin can fix it. This article led to our solution: https://github.com/microsoft/mdatp-xplat/tree/master/macos/upgrade_from_2506_helper

    I found that page linked from here: https://learn.microsoft.com/en-us/answers/questions/5594918/microsoft-defender-for-endpoint-on-macos-fails-to

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