On this page:
1) How to fix Unhandled Exception Error on NinjaTrader - Troubleshooting
2) How to fix Unable to write cache data
1)Unhandeled Exception error:
this process cannot access the file c:\users\Documents\NinjaTrader8\_Workspace.xml or UI.xml files
because it is being used by another process
This error indicates that something on Windows is preventing NinjaTrader from accessing its files. Or Windows settings, or Antivirus settings, or folders settings. and it is not the NinjaTrader Platform problem.
Please test for the error after completing each of the possible solutions below:
1. Reinstall the NinjaTrader Desktop App
You mentioned that you had already reinstalled the platform, so you can move on to the next step if you already followed this step.
Reinstalling NinjaTrader won't affect your custom settings.
Close all running applications.
Do not modify the Documents/NinjaTrader folder.
Uninstall NinjaTrader via the Windows Settings menu
Navigate to C:\Program Files and delete the NinjaTrader 8 folder if it exists.
Reboot your PC.
Download and reinstall NinjaTrader from the Download page on your NinjaTrader Account Dashboard.
Before restarting, ensure Windows is up to date (Windows Settings > Update & Security). Manually check for updates and reboot if needed.
2. Check Windows Firewall/Anti-Virus
Ensure your firewall, antivirus, or backup software is not interfering with NinjaTrader. Add exceptions for NinjaTrader in these programs.
3. Verify the NinjaTrader Documents folder has proper permissions
Navigate to the Documents folder.
Right-click on NinjaTrader 8 > select Properties.
Ensure Read-only and Hidden attributes are unchecked.
When prompted, select Apply changes to this folder, subfolders, and files > click OK.
4. Disable Controlled Folder Access
Press the Windows Key and search for "Controlled Folder Access."
Select Controlled Folder Access and turn it off (if enabled).
Note: Administrator rights may be required to change this setting. Contact your network/PC administrator if needed.
For additional details on Controlled Folder Access, refer to Microsoft's official documentation.
If the problem remains, you can fix this problem (I guarantee it) by reseting your windows installation to initial version.
To reset a Windows 11 installation, go to Settings > System > Recovery > Reset this PC, then choose whether you want to "Keep my files" for a refresh or "Remove everything" for a full reinstall, and follow the on-screen instructions to complete the process; make sure to back up your important data before resetting your computer.
Delite/removey/rename NinjaTrader Folders:
- MyDocuments/NinjaTrader8
- c:/Program Files/NinjaTrader 8
Key steps:
- Access Settings: Open the Start menu and click on "Settings".
- Navigate to Recovery: Select "System" then "Recovery".
- Initiate Reset: Click "Reset this PC".
- Choose Option: Select "Keep my files" to keep personal data or "Remove everything" to completely wipe the drive.
- Confirm and Reset: Follow the on-screen instructions to confirm your choice and start the reset process.
Download latest installation NinjaTrader platform from ninjatrader.com and install. Test it this installation prior to install any indicators to make sure it works well.
2) How to fix NT8 error " Unable to write cashe data ":
1) Please delete your cache, hide your locally stored historical data
To delete the cache and hide your historical data, follow the steps below.
- Shut down NinjaTrader.
- Open the Documents > NinjaTrader 8 > db folder.
- Delete the sub-folder named 'cache'.
- Rename the 'day', 'minute', and 'tick' folder to 'dayOLD', 'minuteOLD', and 'tickOLD'.
2) start NinjaTrader in Safe Mode:
To enable safe mode, please use the following steps:
* Ensure NinjaTrader is shut down
* Hold the CONTROL key and double click the NinjaTrader icon.
* Keep the CONTROL key held down until you see the Control Center.
* You can verify you are in safe mode by going to Help -> About.
Once NinjaTrader has started on just the control center, please open a new chart with no custom bar types/indicators/templates and test for issues.
If there are no issues on this new workspace, please try opening the previous workspace by going to the Control Center > Workspaces > Choose your workspace.
If there are no issues, restart NinjaTrader normally and test for issues.
If this reintroduces issues, I would suggest rebuilding your workspace,
3) How to rebuild your workspace:
- adding 1 indicator at a time.
Please keep track of what indicators you add back in so that we can narrow down what indicator is causing the issue if the issue returns.