How to Fix "App.pkg” can’t be opened because Apple cannot check it for malicious software.

[devinschumacher]

If you're trying to open an app or installer on your Mac and seeing this error:

"App.pkg” can’t be opened because Apple cannot check it for malicious software.

That is the default warning that appears appears for any app that isn’t “notarized” by Apple — which includes many tools from small developers, open-source apps, or beta software.

Always make sure you downloaded the file from a trusted website or developer. As long as you trust the source, it’s safe to bypass.

Video walkthrough

Steps to fix

1. Double click to install the package (expect to see the warning).
2. Go to System Settings / Privacy & Security
3. Scroll down — you’ll see a message saying the app was blocked.
4. Click: `Open Anyway"

5. Confirm you want to open the file when asked to enter your password

That’s it — now the installer will launch normally.