We are aware of an issue that can cause the installation or reinstallation of Avast applications to fail intermittently on macOS 27 (Golden Gate).

When this issue occurs, the installer may display the following message:

• The installation failed. The installer encountered an error...

This issue is intermittent and does not affect every installation attempt. To resolve this Error, you should delete the old setup file(s) and re-download a fresh setup file from your Avast Account and try installing again. For detailed instructions, refer to the section below:

Step by step instructions

Step 1: Delete the old Avast setup file from the Downloads folder

1. Open Finder.
2. Select Downloads from the sidebar.
3. Locate the Avast setup file. The file name begins with Avast and ends with .dmg.
4. Select the file, right-click it, then select Move to Trash.
5. Open Trash, then click Empty Trash.

If the file cannot be deleted, close the Avast installer window if it is open, then check whether the installer is still mounted and unmount it using the steps below.

Verify and unmount the Avast installer

1. Open Finder.
2. In the sidebar, look under Locations for a mounted Avast installer volume.
3. Click the Eject icon next to the Avast volume. Alternatively, select the volume, right-click on it, then select Eject.
4. Wait for the Avast volume to disappear from the Finder sidebar.
5. Open Downloads, select the Avast .dmg installer, right-click it, then select Move to Trash.

Step 2: Download and install the Avast app

1. Sign in to your Avast Account.
2. Enter your email address and click Continue.
3. Choose one of the following sign-in methods:
   • Sign in using your password: Enter your password, then click Sign In.
   • Sign in with a one-time passcode: Click Request one-time passcode. Enter the passcode, then click Verify.
   • Sign in with a third-party account: Select Google, Apple ID, or Microsoft, if the account is already linked.
4. Go to My Subscriptions and click Manage subscriptions.
5. Find your Avast app on the list and click Download.
6. Select Download on this Mac and click Continue.
7. Depending on the Avast app being installed, select one of the following products, then refer to the Mac instructions:
   • Avast One
   • Avast Premium Security
   • Avast SecureLine VPN
   • Avast Cleanup
   • Avast AntiTrack
   • Avast BreachGuard

The Avast app is now installed on your Mac.

Updated on: 14/09/2026