If you're experiencing repeated login prompts, CAPTCHA loops, or issues connecting to your prop accounts on NinjaTrader 8 (NT8), please follow the steps below carefully. These steps move from the most common fixes to more advanced session/device resets.
⚠️ Before You Begin
Make sure NinjaTrader 8 is completely closed before performing any of the steps below.
To confirm it’s fully closed:
Right-click your taskbar → select Task Manager.
End any running processes named NinjaTrader.exe or NinjaTrader 8 (32-bit).
Once confirmed, proceed with the steps below.
Step 1: Sync Your System Clock
Incorrect system time is one of the most common causes of login loops and CAPTCHA failures.
Right-click the clock in the bottom-right corner of your Windows desktop.
Select Adjust date and time.
Make sure Set time automatically is ON.
Scroll down and click Sync now under "Synchronize your clock."
Wait for confirmation that it says: "Time was successfully synchronized."
✅ Once complete, reopen NinjaTrader 8 and try logging in again.
Step 2: Flush Your DNS Cache
If the issue persists, your DNS cache may be pointing to an outdated authentication endpoint. Follow these steps to refresh it:
Close NinjaTrader completely (as above).
Open the Start menu, type cmd, right-click Command Prompt, and choose Run as administrator.
Type the following command and press Enter:
ipconfig /flushdns
You should see a message confirming: "Successfully flushed the DNS Resolver Cache."
✅ Now try launching NinjaTrader again and log in.
Step 3: Reset Session and Device Recognition
If you're still stuck in a CAPTCHA loop or repeated login prompts after Steps 1 and 2, the issue is likely tied to a stale session or device-trust state. The following steps have helped other users break the loop by forcing NinjaTrader to regenerate its local session data and re-establish device trust through 2FA.
Make sure NinjaTrader 8 is fully closed (see "Before You Begin") before starting.
1. Clear the NinjaTrader cache
Navigate to your NinjaTrader 8 user folder (typically Documents\NinjaTrader 8\) and delete the cache folder. NinjaTrader will recreate it automatically the next time it launches.
2. Rename the NinjaTrader.sqlite file
In the same NinjaTrader 8 folder, locate NinjaTrader.sqlite and rename it (for example, to NinjaTrader.sqlite.bak). This forces NinjaTrader to generate a fresh database on next launch. Keeping the renamed copy preserves your old data as a backup in case you need to restore it.
3. Log into the NinjaTrader web dashboard
In your browser, sign in to your NinjaTrader account at the web dashboard. This confirms your credentials are valid and lets you manage your security settings directly.
4. Enable 2FA (if not already enabled)
Within the web dashboard's account/security settings, enable two-factor authentication (2FA) if it isn't already on. 2FA is what allows NinjaTrader to properly recognize and trust your device on the next login attempt.
5. Remove or unlink any previously recognized devices
Still in the dashboard, find the list of trusted/recognized devices and remove any old or unfamiliar entries. This clears any stale device-trust records that may be causing the loop.
6. Restart the VPS
If you're running NinjaTrader on a VPS, restart the VPS before attempting to log in again. This ensures no lingering NinjaTrader processes or cached network state remain.
7. Log back in and approve the device via 2FA
Launch NinjaTrader 8 and attempt to log in. You should receive a 2FA prompt to approve the device. Approving it here re-establishes a clean device-trust relationship and typically resolves the CAPTCHA loop.
Still Having Issues?
If you've worked through all of the steps above and are still unable to log in, please reach out to our support team and let us know:
Which steps you've already completed
Any error messages you're seeing
Whether you're connecting from a local machine or a VPS
We're happy to walk through any of the steps above with you and help get you back into your account.
For additional reference, see NinjaTrader's official troubleshooting documentation.