Short Answer 
To resolve D3D12 application issues, start by updating your Nvidia graphics driver from the official site. If problems persist, perform a clean installation of the driver, and if necessary, consider rolling back to a previous version or checking for Windows updates and application updates.
Step 1: Update Your Nvidia Graphics Driver
Start by ensuring that you have the latest version of your Nvidia graphics driver. To do this, visit the Nvidia Driver Downloads page and input your graphics card details. Download and install the most recent driver version to improve compatibility and performance in D3D12 applications.
Step 2: Perform a Clean Installation
If issues persist after updating, it’s essential to do a clean installation of the graphics driver. This entails removing any previous driver versions completely to avoid conflicts. During the installation process, choose the ‘Custom’ installation option and check the ‘Perform a clean install’ box to ensure a fresh setup.
Step 3: Rollback or Check for Updates
If the problem continues, consider rolling back to a previous driver version that functioned without issues. To rollback, access the Device Manager, locate your graphics card under ‘Display adapters’, and use the ‘Roll Back Driver’ option. Additionally, check for Windows updates, as these may contain crucial fixes, and ensure that any applications experiencing problems are updated to their latest versions.