: If your game started crashing after the April 20, 2026 update, right-click CK3 in your Steam Library : Properties > Betas > Beta Participation and select an older version like 1.18.4 (Crane) .
: 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. ck3-crash
: Right-click CK3 in Steam: Properties > Installed Files > Verify integrity of game files . This repairs corrupted data that often causes startup crashes. : If your game started crashing after the
: Windows 11 users (specifically version 24H2) may face unique compatibility issues that Paradox is actively working to resolve. ck3-crash