MS Defender - Installation Error version 101.25072 on macOS

First check /Library/Logs/Microsoft/mdatp/install.log on your device. Hopefully you'll find more detailed information in why the installation fails.

You can also check if Microsoft Defender and MDE Security Extension has full disk access on your MAC. If not, change to full access and don't forget to restart your MAC. After reboot, try the install again.

+1 Same error on various M Mac models.

+1

Getting the same error. On intel running Macos 15.6.1 (24G90)

Hi Yasin,

Thanks for sharing this—I've seen similar issues with Microsoft Defender updates on macOS, especially when AutoUpdate gets stuck or misaligned with system permissions.

Here are a few things you might try:

• Clear the AutoUpdate cache (look under ~/Library/Application Support/Microsoft/MAU).
• Try a manual install: download the latest Defender build directly from Microsoft instead of using AutoUpdate.
• Check permissions: make sure Defender and AutoUpdate have full disk access under System Settings → Privacy & Security.
• If your device is managed with Intune, review update policies that might be interfering.

If none of those help, it’s worth opening a Microsoft Support case—especially since it’s persisted across networks and restarts.

Hope that helps, and thanks again for raising it!