Please do a full **clean** re-install:
- move any valued save games elsewhere
- "uninstall" in Steam-CK3
- manually delete both the Steam/SteamApps/common/CK3 AND Documents/Paradox Interactive/CK3 folders
- re-install game in Steam, run a Steam Verify when done.
- add CK3.exe to the exceptions list of your antivirus app; ESPECIALLY if you have Windows Defender, add it to the Ransomware "Apps Allowed Through" list.
- start the game with no mods active and test with a new campaign - NOT with any existing one
In particular make sure there are no files or folders left under either the Steam CK3 or Documents CK3 locations, before installing again.
If you still get this problem then, when the game crashes what happens? Can you start it right up again, or you need to reboot or wait a while before it will run again?
Please report the temperatures of your CPU and video (GPU)
1/ before start...
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