Unfortunately, nothing helps. I tried all three points in your message.
I also tried these tips, but they didn’t help either.
Verify file integrity
The simplest, but often forgotten:
Right-click on “No Rest for the Wicked” in the Steam library.
Properties > Installed Files.
Click “Verify Integrity of Game Files.”
Software Conflict (NVIDIA and Overlays)
Error 51 is often caused by programs attempting to “hack” into the game process.
Overlays: Try temporarily disabling the Steam in-game overlay and NVIDIA Shadowplay.
Third-party utilities: If you use MSI Afterburner or RivaTuner for monitoring, close them before launching.
Drivers: Make sure your NVIDIA control panel settings don’t conflict with experimental driver features. A clean driver reinstall via DDU can sometimes help if standard methods don’t work. 3. Visual C++ Libraries
The game requires up-to-date library sets. If they are corrupted, this error will occur.
Go to Control Panel > Programs and Features.
Find all versions of Microsoft Visual C++ Redistributable (especially 2015-2022).
Right-click them, select Change, and then select Repair.
Antivirus and Permissions
Add the game folder to your antivirus (or Windows Defender) exceptions.
Try running Steam as an administrator.
Clearing the shader cache: Delete the contents of the %LocalAppData%\NVIDIA\DXCache folder (with the game closed). The new build from January 26th may attempt to use older shaders, which causes a crash. Resetting the game to default settings: Try running the latest version after deleting the configuration file (usually in AppData/Local/NoRestForTheWicked/Saved/Config). Sometimes graphics settings from older patches are incompatible with newer ones.
Disabling fullscreen optimization: Find the game’s executable file (NoRestForTheWicked.exe), right-click > Properties > Compatibility > check “Disable fullscreen optimization.” This often resolves error 51 when using specific gamma settings in the driver.
According to Truly [UBW] on Discord, this issue is caused by the anti-virus blocking the game files. Launching the game from the exe leads to application load error 3:00000065432, which is also mentioned in this post:
This can be easily resolved by excluding said files in the anti-virus. Source