What is the issue?

Some users on Windows 10 and Windows 11 are experiencing issues with the Nx Witness Desktop client, including crashes or the application not opening at all. These problems often occur shortly after launching the client or when working with layouts that include multiple items. In some cases, users have also reported memory leaks or slow performance.

When a crash occurs, it may be accompanied by the following error message or a similar one:

What is the cause of the issue?

The underlying issue is related to OpenGL support. Many modern graphics drivers, especially those for Intel integrated GPUs and some NVIDIA GPUs, do not fully support OpenGL on Windows. As a result, the default graphics rendering option used by the Nx Witness Desktop client (OpenGL) can lead to crashes and instability.

What is the short term solution?

Force the Nx Witness Desktop client to use DirectX

1. Close the Nx Witness Desktop client
2. Create a directory called nx_ini at the location below, if it does not already exist.
   C://Users/<username>/AppData/Local/
3. In the nx_ini directory, create a blank .ini file called desktop_client.ini.
   Optional: Start the Nx Witness Desktop client once, it should generate all default values for this file, and close the Desktop client again.
4. Open the desktop_client.ini file with a text editor, like Notepad.
5. Add or change the following line, and save your changes:
   graphicsApi="direct3d11"
6. After launching the Nx Witness Desktop client, you can verify that the graphics API has changed in the About (F1) window of Nx Witness Desktop client.

Downgrade to a stable NVIDIA driver if using OpenGL

You may consider installing NVIDIA driver version 32.0.15.5639, which has been tested and is known to work reliably in many cases. However, results can vary depending on the specific hardware configuration of your system.

What is the long term solution?

Starting from version 6.1, the Nx Witness Desktop client uses a new Rendering Hardware Interface (RHI) that supports multiple graphics API backends. This allows the Nx Witness Desktop client to automatically use the most suitable rendering option for your system: Direct3D (default on Windows), Metal (macOS), Vulkan (default on Linux if supported by the graphics card), or modern OpenGL (used on Linux when Vulkan isn't available).