How To Fix A Firewall May Be Blocking Spotify ( Error Code: auth:16) On Windows 10/11

When you try to log into Spotify’s desktop app and see:

“A firewall may be blocking Spotify. Please update your firewall to allow Spotify. (Error code: auth:16)”

…it means Spotify cannot properly communicate with its servers because something (a firewall, antivirus, proxy, or network setting) is blocking or interfering with it.

People in Spotify’s Community forums have noted that even when firewall rules look fine, antivirus or proxy settings, or entries in the hosts file, can still cause this error.

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🛠 Step-by-Step Fixes for Spotify Error auth:16

Try these solutions in order. After each, test if you can log into Spotify.

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1. Allow Spotify through Windows Firewall

1. Press Windows + R, type firewall.cpl, press Enter.
2. Click “Allow an app or feature through Windows Defender Firewall”.
3. Click Change settings.
4. In the list, find Spotify, and check both Private and Public boxes.
5. If Spotify is not listed, click Allow another app → Browse, find Spotify.exe (in the installation folder) and add it.
6. Click OK.
7. Restart Spotify and try logging in.
   • This is a commonly recommended fix.

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2. Set Spotify Proxy to “No Proxy”

Spotify’s proxy setting may interfere with login.

• Open Spotify’s login screen.
• Before entering credentials, look for Settings (gear icon or similar) on that screen.
• Scroll down to Proxy section.
• Set Proxy type to “No Proxy” (or disable proxy).
• Restart Spotify and log in again.
  • Many users report this step resolves auth:16.

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3. Check / Reset Hosts File

If your system’s hosts file has entries redirecting Spotify domains, that can block the service.

1. Navigate to C:\Windows\System32\drivers\etc\.
2. Open the hosts file in Notepad (run Notepad as administrator).
3. Look for any lines containing spotify, fastly, or related server names (e.g. 0.0.0.0 weblb-wg.gslb.spotify.com).
4. If found, delete those lines or comment them out (place # at start).
5. Save the file.
6. Restart Spotify.
   • Several users resolved the error this way.

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4. Temporarily Disable Third-Party Antivirus / Firewall

Your antivirus or a third-party firewall may block Spotify even when Windows firewall allows it.

• Locate your antivirus / firewall icon in system tray.
• Temporarily disable it or turn off real-time protection.
• Try logging into Spotify.
• If it works, add Spotify as an exception/whitelist in your antivirus or firewall settings.
  • One user resolved error auth:16 by disabling Kaspersky, for example.

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5. Use a Different Network / Hotspot

To test if the issue is specific to your current network:

• Switch off Wi-Fi / connect to your mobile phone’s hotspot.
• Launch Spotify and try logging in.
• If it works on another network, your original network may have restrictions (router firewall, ISP blocking, etc.).

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6. Reinstall Spotify (Clean Install)

Sometimes the app cache or installation is corrupted.

1. Uninstall Spotify from Settings → Apps.
2. After uninstalling, delete leftover folders (if any), such as in C:\Users\<YourName>\AppData\Roaming\Spotify and C:\Users\<YourName>\AppData\Local\Spotify.
3. Download the latest Spotify installer from the official site.
4. Install and try logging in again.
   • This is often a last resort, but necessary if the installation is broken.

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7. Restart Network Devices & Computer

• Power cycle your router / modem (unplug for 30 seconds, then plug back).
• Restart your PC.
• Sometimes network issues or temporary glitches cause auth errors.
  • This is a basic but sometimes effective step.