Not connected, or the connection keeps dropping in NinjaTrader 8

What is causing it

Usually wrong credentials for the data or broker connection, the wrong connection profile selected, the provider being in its daily maintenance window, or a firewall blocking NinjaTrader.

Why this happens

NinjaTrader is only the front end. The username and password on a connection belong to whoever supplies the data and order routing, and NinjaTrader simply passes them on. If the provider rejects them, NinjaTrader has nothing to display and shows a disconnected state.

Repeated drops at the same time each day are almost always the provider's scheduled maintenance, not your machine. Drops at random times are more often a network or security-software problem.

The fix, step by step

1. Open the Control Center and use the Connections menu to check which connection you actually launched, as many users have several saved.
2. Choose Configure in the Connections menu and re-enter the username and password for that connection, remembering these are your broker or data provider credentials, not your NinjaTrader account login.
3. Confirm you selected the correct environment for that provider, because most futures providers have separate live and demo or simulation servers and the credentials are not interchangeable.
4. Check the time. Futures data providers take a daily maintenance break and a weekly weekend break, and no connection will hold during it.
5. Allow NinjaTrader through Windows Firewall and any third-party security software, then restart the platform.
6. If it still fails, contact the provider named on the connection (your broker, or Rithmic, CQG or Kinetick) rather than NinjaTrader support, since they own the login.

How to confirm it is fixed

The connection status in the Control Center stays green through a full trading session, and a chart on a liquid front-month contract prints new bars in real time.

Stopping it happening again

Keep one clearly named connection per provider and delete old ones you no longer use. Note your provider's maintenance window so a nightly disconnect does not look like a fault.