: Right-click CK3 in Steam: Properties > Installed Files > Verify integrity of game files . This repairs corrupted data that often causes startup crashes.
: In the Paradox Launcher settings, change the "Renderer" between Vulkan and DirectX 11 (DX11) . Some systems run significantly more stably on one than the other. Troubleshooting Common Causes ck3-crash
: Disable all mods in the launcher and try to start a new game. If it works, re-enable mods one by one to find the culprit. : Right-click CK3 in Steam: Properties > Installed