At D:\a\d\e2af82edaa31c93c6098ffbd561125ed\b0be1561439953a6\stingray\runtime\d3d12_render_device\d3d12_debug.cpp:1634 in function stingray::aftermath::d3d_assert
Hm okay, when installing fresh GPU drivers, did you use a dedicated driver removal tool beforehand?
If not, I recommend using DDU (Display Driver Uninstaller) in safe mode, to nuke your existing drivers, and then to reinstall cleanly.
Another suggestion, though a shot in the dark, as you have a Ryzen CPU is to check for any available BIOS updates. Though the error indicates a GPU issue, outdated BIOS can lead to general instability so it could be worth looking into. With firmware updates we advise caution and to do so at your own risk.
Lastly, to rule out anything amiss with your game files or settings, you could try deleting AppData and verifying files - but ensuring that Steam Cloud Save is disabled:
Step 1: Disable Steam Cloud Saving
If Steam Cloud saving is enabled for Darktide, this may automatically restore the AppData and consequently cause the issue to resurface.
Navigate to your Steam library
Right-click Darktide
Select ‘Properties’
On the ‘General’ tab, scroll down to ‘Steam Cloud’
Disable ‘Keep game saves in the Steam Cloud for Warhammer 40,000: Darktide’
Step 2: Delete AppData NOTE: By deleting your AppData, operative loadouts and custom keybindings will be reset. You may wish to make a back-up of the directory in the event deleting your AppData does not work to resolve the issue.
Press the Windows key + R
Enter %appdata% within the search input and select ‘OK’
Navigate to: AppData\Roaming\Fatshark
Delete the entire ‘Darktide’ directory
Step 3: Verify Integrity of Game Files
You will then need to use the ‘Verify Integrity of Game Files’ option, which is accessible via the Steam client and will ensure the installation is complete.
Right-click Darktide in your Steam library sidebar
Select ‘Properties’
Select the ‘Local Files’ tab
Select the ‘Verify Integrity of Game Files’ button