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NinjaTrader Disconnections – How to Diagnose and Fix

Steps to troubleshoot disconnections from NinjaTrader servers.

Updated this week

When NinjaTrader disconnects from your broker or data feed, it may appear as if the platform or VPS is at fault — but in most cases, the root cause is related to the network path between NinjaTrader and your broker’s servers.

This article outlines how to diagnose these issues and determine whether the problem is local (VPS-related) or external (broker-related).


Common Causes of Network Disconnections

  1. User-Induced Disconnections: Disconnections can occur when NinjaTrader is manually shut down or restarted, whether done manually or via automated scripts or plugins. This action disrupts all active connections.

  2. Network Path Issues: Connection issues can arise from problems along the network path between your VPS and the broker's servers. These may include routing disruptions or firewall interference.

Step 1: Check NinjaTrader Log & Trace Files

NinjaTrader maintains detailed diagnostic logs that often explain the disconnection reason.

How to retrieve your log and trace files:

  1. Close NinjaTrader completely

  2. Open File Explorer

  3. Go to: Documents > NinjaTrader 8

  4. Locate the folders named “log” and “trace”

  5. Right-click each folder → Copy

  6. Paste them to your desktop or any easy-to-access location

  7. Upload the relevant .txt files in your reply to support or review them yourself

Look for messages such as:

  • WebSocket closed

  • An existing connection was forcibly closed by the remote host

  • Authentication failed

  • Repeated login attempts

  • Errors referencing your broker (e.g., Tradovate, Rithmic, Apex)

You can also submit these directly to NinjaTrader using their official instructions:


Step 2: Check Network Connectivity on Your VPS

To confirm whether your VPS lost network access during the disconnection:

👉 Follow this guide to check your Windows Event Viewer logs:

Alternatively, go to your QuantVPS dashboardMonitoring tab.

If there are no periods where both inbound and outbound = 0, your VPS network was healthy, and the issue is likely with the broker or data feed.

Additionally, brokers like Rithmic may experience traffic limitations or temporary service outages during high-traffic periods. These external factors can often lead to recurring disconnection issues, especially during busy trading times.

no network connections

Scheduled Maintenance

If a maintenance banner appears while trying to access NinjaTrader, it indicates scheduled maintenance controlled by NinjaTrader. These outages typically occur during weekends or after trading hours and resolve automatically once the maintenance period ends.


Step 3: Optimize Your Environment

To reduce the chances of future disconnections:

Add NinjaTrader to Windows Firewall

  1. Open Windows Defender Firewall

  2. Click “Allow an app through firewall”

  3. Click “Change settings” > “Allow another app”

  4. Browse to: C:\Program Files\NinjaTrader 8\bin

  5. Select NinjaTrader → Allow both Private and Public networks

Browse to C:\Program Files\NinjaTrader 8\bin

Flush DNS Cache

  1. Open Command Prompt

  2. Run: ipconfig /flushdns

  3. Press Enter


🤝 Need Assistance?

If any part of the setup feels unclear, the QuantVPS team is happy to help. If you’d like us to verify your environment from our side, feel free to open a support ticket and get connected with the team: https://www.quantvps.com/

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