Defender Anti-Malware installer doesn't recognize it's turned on

Hello Jay Townsend

From your description, Microsoft Defender is already enabled in macOS Privacy & Security, but the Defender setup still says the anti-malware setup is incomplete and keeps sending you back to the same settings page.

First, please check the Defender file access permission. Microsoft Defender needs permission to access files because it scans apps and files for threats. Go to System Settings > Privacy & Security > Full Disk Access, then make sure Microsoft Defender is enabled. If you also see Microsoft Defender Extension or Microsoft Defender Endpoint Security Extension, enable that as well.

Optional: If you installed the app using Microsoft’s downloaded package, also check System Settings > Privacy & Security > Security and make sure Allow applications from is set to App Store & Known Developers, not App Store only. The “App Store only” setting may prevent macOS from properly allowing the app or its components.

Once those are enabled, reopen Defender and check whether any Allow, Details, or system extension approval prompt appears. If it still loops after all permissions are allowed, reinstalling Defender from Microsoft’s official Mac download page following the provided the Mac setup instructions.

Please let me know how it goes after trying these steps, and I'll be glad to continue looking into it with you.

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The settings and permissions suggested were already in place. And yes, I triple-checked all of them again, following along with your instructions in case I had missed something on my own prior to submitting my original request for support. The version of Defender at the link provided (and which is where I originally downloaded it from) is for version 101.26022.0020, which is NOT the latest version (101.26032.0016). That means attempting to reinstall the old version over the newer one fails (as shown in the screen capture). And Defender keeps insisting that the Anti-Malware tool hasn't been activated and will not let me past Step 1 because it doesn't recognize that all the permissions and security settings it requires are already in place, so the set-up wizard never advances. As noted in my original request, turning all those settings off, rebooting, and then re-enabling them during the set-up wizard does not resolve anything. The set-up wizard still does not seem to recognize that the Defender settings and permissions have been enabled and never advances. Rebooting again does not change anything. The Anti-Malware tool (see second screen capture) is still stuck at the "Get Started" stage and does not progress to Step 2 after turning all the required toggle switches on and enabling all the other settings. The rest of the Defender app seems to be OK. It's only the Anti-Malware tool that seems to be stuck.