NZBGet 502 Error: Quick Fix Guide

Seeing a 502 error in NZBGet? This error most often points to authentication problems with your Usenet server, but can also mean the NZBGet interface isn’t responding correctly.

This guide covers both situations, starting with the more common: 502 - Authentication Failed.

502 - Authentication Failed (Usenet Server Login Issue)

This error means NZBGet couldn’t log in to your Usenet provider. It’s often caused by:

• Incorrect username or password
• Expired or inactive subscription
• Too many simultaneous connections

Step 1: Check Username and Password

In NZBGet:

• Go to Settings > News-Servers
• Confirm your username and password are exactly as shown in your Usenet provider’s control panel.
• Avoid extra spaces or invisible characters when pasting.

Step 2: Confirm Your Account Is Active

Log into your Usenet provider’s website to confirm your subscription is active and hasn’t expired, been canceled, or suspended.

Step 3: Reduce Connection Count

Some providers limit the number of simultaneous connections. Using too many may result in errors.

• In Settings > News-Servers, reduce the Connections value to 10–20 and test again

Step 4: Restart NZBGet

After making changes:

• Click System > Reload
• Or, use the terminal: nzbget -Q && nzbget -D

This refreshes NZBGet’s connection attempts using the updated login settings.

502 Error Loading NZBGet Web Interface

If you’re getting a 502 error while trying to access the NZBGet interface in your browser, the problem is likely with the daemon or port configuration.

Step 1: Check if NZBGet Is Running

On Linux/macOS: ps aux | grep nzbget

Start it if needed: nzbget -D

On Windows: Use Task Manager or relaunch from the Start Menu.

Step 2: Try Accessing by Direct Port

Open your browser to: http://localhost:6789

Or: http://<your-device-ip>:6789

Step 3: Check Port and IP Settings

In nzbget.conf or via Settings > SYSTEM:
ControlPort=6789
ServerIp=127.0.0.1

Make sure these values aren’t changed or conflicting with another service.

Step 4: Check NZBGet Logs

View the logs to look for issues:

• Windows: Application folder or %AppData%\nzbget
• Linux/macOS: ~/.nzbget/nzbget.log

Common log errors:

Error: Could not bind to port

Error: Daemon failed to start

Error: Authentication failed

Step 5: Bypass or Fix Reverse Proxy

If using a reverse proxy like Nginx, temporarily bypass it and connect directly. If the error disappears, correct your proxy configuration.

Example Nginx config:

location /nzbget/ {
    proxy_pass http://127.0.0.1:6789/;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
}

Additional Tips

• Try accessing from an incognito window or different browser
• Disable firewall/antivirus temporarily to rule out blocking
• If problems persist, back up your configuration and reinstall NZBGet