If you’re using Mac OS 10.9.5 (or higher), your Mac’s settings may allow you to open only apps installed from the Mac App Store. This article walks you through how to adjust your Mac’s settings so you can install and open Firefox Marketplace apps. To learn how your Mac's security settings affect the apps you download, please visit Apple Support.

Install the app

1. When you find an app that you would like to install, tap the blue button. If the app is free, the button will say that. If the app costs money, the price will be listed on the button.

   

2. Confirm that you want to install the app by tapping the Install button on the prompt.

   

3. Your app will download and appear in your Mac's Applications folder.

   

Open the app

Double-click the app's icon in your Applications folder. If the app opens right away, start using it!

If you see the following security message, it means your Mac's settings allow you to open only apps downloaded from the Mac App Store. Let's fix that:

1. Click OK to close the message.

   

2. Now open your Mac's System Preferences (by clicking on the Apple logo on the top left corner of your screen) and click the Security & Privacy icon.

   

3. Click the Open Anyway button in the General tab. This tells your Mac that it's okay to open the Firefox Marketplace app you just downloaded.

   You'll need to do this once for each app that you download.

   

4. Click Open to confirm that you want to open the app. Now start using your app!

   

Learn more about Firefox Marketplace

• Marketplace apps for Firefox Desktop
• Use Firefox Accounts to manage your Marketplace apps