When the firewall is enabled, click the Advanced button to set firewall options. To turn the firewall on with only Mac OS X application exclusions, click Block All Incoming Connections. To turn the firewall on with exclusions, click Automatically Allow Signed Software to Receive Incoming Connections. Every time I try to download a program my computer says that my security settings will not aloow the file to downloaded,help! This thread is locked. You can follow the question or vote as helpful, but you cannot reply to this thread. See alsoIf you’re asked for an administrator name and password on Mac Use Touch ID on Mac Use the Touch Bar on Mac Helpful?

Available only on Mac computers that have the Apple T2 Security Chip, Startup Security Utility offers three features to help secure your Mac against unauthorized access: Firmware password protection, Secure Boot, and External Boot.

When the firewall is enabled, click the Advanced button to set firewall options. To turn the firewall on with only Mac OS X application exclusions, click Block All Incoming Connections. To turn the firewall on with exclusions, click Automatically Allow Signed Software to Receive Incoming Connections. Aug 05, 2012 I downloaded MPlayerX from the Mac AppStore but it still doesn't allow it to run. I have to change the settings to 'Anywhere'. This is annoying. After restarting my computer, it will revert to Quicktime as the default player even though I have set MPlayerX as the default prior to shutting down my computer. Click the Security tab, click on Internet, and then click the Custom level button. Scroll down to the Downloads category, and set File download to Enable & Automatic prompting for file downloads to Enable. Click OK, and then click Yes.

To open Startup Security Utility:

1. Turn on your Mac, then press and hold Command (⌘)-R immediately after you see the Apple logo. Your Mac starts up from macOS Recovery.
2. When you see the macOS Utilities window, choose Utilities > Startup Security Utility from the menu bar.
3. When you're asked to authenticate, click Enter macOS Password, then choose an administrator account and enter its password.

Firmware password protection

How To Change Security And Privacy Settings On Mac

Free download avant browser for mac. Use a firmware password to prevent anyone who doesn't have the password from starting up from a disk other than your designated startup disk. To set a firmware password, click Turn On Firmware Password, then follow the onscreen instructions. Learn more about firmware passwords.

Security Settings Do Not Allow Downloads. - Microsoft Community

You can also use External Boot to prevent even those who know the firmware password from starting up from external media.

Secure Boot

Allow Security Setting To Download Macbook Pro

Use this feature to make sure that your Mac starts up only from a legitimate, trusted operating system. Learn more about Secure Boot.

External Boot

Use this feature to control whether your Mac can start up from an external hard drive, thumb drive, or other external media. The default and most secure setting is ”Disallow booting from external media.” When this setting is selected, your Mac can't be made to start up from any external media:

• Startup Disk preferences displays a message that your security settings do not allow this Mac to use an external startup disk.
  
• Startup Manager allows you to select an external startup disk, but doing so causes your Mac to restart to a message that your security settings do not allow this Mac to use an external startup disk. You'll then have the option to restart from your current startup disk or select another startup disk.

To allow your Mac to use an external startup disk:

1. Open Startup Security Utility.
2. Select ”Allow booting from external media.”
   Your Mac doesn't support booting from network volumes, whether or not you allow booting from external media.
3. If you want to select an external startup disk before restarting your Mac, quit Startup Security Utility, then choose Apple menu  > Startup Disk.