Microsoft 365 and Office | Microsoft 365 Defender | Other | Other
An integrated threat protection solution designed to detect, investigate, and respond to cyber threats across Microsoft 365 services.
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had to uninstall defender causing bug issues, now can not reinstall
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Claude Pereira
0
Reputation points
C
Microsoft 365 and Office | Microsoft 365 Defender | Other | Other
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Rukmini 41,725 Reputation points Microsoft External Staff Moderator2026-04-20T01:34:31.56+00:00 - Which macOS version are you running (e.g. 11.5 Big Sur, 12.x Monterey, 13.x Ventura)?
- Did you fully reboot after uninstalling Defender before trying to reinstall?
- What exact uninstall method or tool did you use to remove Defender initially?
- Are there any error codes or more detailed messages in your install.log? You can view this in Console.app
- Have you checked System Settings → Privacy & Security to see if any Microsoft system extensions are blocked?
- Did you try installing the latest Defender for Endpoint for Mac PKG from your company portal or directly from Microsoft?
- If you run the install from Terminal with sudo, what output do you get
Once we have those details, we can dive deeper into permissions or leftover components that might be preventing a clean reinstall.
Note: This content was drafted with the help of an AI system. Please verify the information before relying on it for decision-making.
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Rukmini 41,725 Reputation points Microsoft External Staff Moderator
2026-04-21T02:24:36.9233333+00:00 Claude Pereira Please confirm whether your issue is resolved or still facing any errors.
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Rukmini 41,725 Reputation points Microsoft External Staff Moderator
2026-04-22T06:55:40.28+00:00 Claude Pereira Thank you for sharing the details will check internally and get back to you!
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Rukmini 41,725 Reputation points Microsoft External Staff Moderator
2026-04-28T01:36:31.47+00:00 Hello Claude Pereira
The installation failure of Microsoft Defender on macOS after uninstall is caused by leftover system components or corrupted previous installation.
It is due to incomplete uninstall cleanup issue on macOS.
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Claude Pereira 0 Reputation points
2026-04-28T08:40:47.2766667+00:00 Thanks for your response, how do i fix this then?
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Claude Pereira 0 Reputation points
2026-04-21T08:59:33.9466667+00:00 Hi Rukmini, thanks for your responce,
see my responses below
1.Tahoe 26.4.1
- Yes
- Move to trash command
- See attachment crash report
- Yes checked and not blocked
- Directly from Microsoft after logging into my account
- Not sure what to do here