How to fix the app can’t be opened because Apple cannot check it for malicious software

The error “This app can’t be opened because Apple cannot check it for malicious software” occurs on macOS when you try to open an app that isn’t signed by an identified developer or downloaded from the Mac App Store. This is part of macOS Gatekeeper security, introduced in macOS Sierra and strengthened in later versions like Catalina, Big Sur, and beyond. Here’s how to fix it step-by-step using built-in macOS tools.

Step-by-Step Solutions This app can’t be opened because Apple cannot check it for malicious software

Here are four solutions to fix that problem: –

Solution 1: Allow the App via System Settings (One-Time Override)

• Try Opening the App:
  • Double-click the app in Finder (e.g., in /Applications or ~/Downloads).
  • You’ll see the error message with “OK” as the only option.
• Open System Settings:
  • Go to Apple menu () > System Settings (or System Preferences on older macOS versions) > Security & Privacy > General tab.
• Approve the App:
  • At the bottom, you’ll see a message: “'[App Name]’ was blocked because it is not from an identified developer.”
  • Click the Open Anyway button next to it.
• Retry Opening:
  • Double-click the app again. It should now launch without the error.
• Note: This option only appears after you’ve tried opening the app once and may require an admin password.

Solution 2: Bypass Gatekeeper via Terminal (Manual Override)

• Open Terminal:
  • Go to Applications > Utilities > Terminal.
• Allow the App:
  • Run this command, replacing /path/to/app with the app’s location (e.g., /Applications/MyApp.app):
    sudo spctl --master-disable sudo xattr -r -d com.apple.quarantine /path/to/app
  • Example:
    sudo spctl --master-disable sudo xattr -r -d com.apple.quarantine /Applications/MyApp.app
  • Enter your admin password when prompted.
• Explanation:
  • spctl --master-disable: Temporarily disables Gatekeeper.
  • xattr -r -d com.apple.quarantine: Removes the quarantine attribute that flags the app as unverified.
• Launch the App:
  • Double-click the app—it should open without the error.
• Re-enable Gatekeeper (Optional):
  • For security, turn Gatekeeper back on:
    sudo spctl --master-enable

Solution 3: Adjust Gatekeeper Settings (Global Change)

• Open System Settings:
  • Apple menu > System Settings > Security & Privacy > General.
• Change Gatekeeper Policy:
  • Under “Allow apps downloaded from,” select App Store and identified developers (default) or look for an option to allow unsigned apps.
  • Note: Since macOS Sierra, the “Anywhere” option is hidden in the GUI but can be enabled via Terminal.
• Enable “Anywhere” Option (Older macOS):
  • In Terminal:
    sudo spctl --master-disable
  • Reopen Security & Privacy—you may see “Anywhere” as an option. Select it.
• Launch the App:
  • Try opening the app again.
• Revert (Optional):
  • Re-enable Gatekeeper:
    sudo spctl --master-enable

Solution 4: Right-Click Open (Quick Workaround)

• Open via Context Menu:
  • In Finder, right-click the app (e.g., MyApp.app) > Open.
  • A dialog appears with an “Open” button (unlike double-clicking, which only shows “OK”).
  • Click Open.
• Why It Works:
  • This method tells macOS you explicitly trust the app, bypassing the initial Gatekeeper check.
• Note: You only need to do this once—subsequent launches work normally.