The registry and Vulkan fixes relate to a problem that can happen under Windows 11 24H2 only, and the typical symptom is a hard-hang of the whole PC, not a game-only crash as you seem to be mentioning here.
That issue affects this game and Vic3 quite badly, but only rarely our other older games. I suspect you have unrelated problems with whichever games you are referring to here.
But let's focus on this game: does this crash happen on game start, creating a campaign, or during play?
If the latter, can you then reload the save and carry on past the crash point? Or it then always crashes at the same point?
Right click on ck3.exe , properties, compatibility. Tick "disable fullScreen optimisations" untick every other box in that dialog, Apply and exit.
Then in the launcher Game Settings menu, select fullScreen display mode, Vsync off, cap refresh rate at 60.
If those don't help:
DXDIAG is a program you run from the Windows search box on the task bar. After running it will open a window and start collecting info with a progress bar in the lower-left corner. When it completes click the 'save all information' button and save it to a file then attach that file here.
IF dxdiag.txt fails to attach here, rename it to dxdiag.log , or zip it up.
Please attach here your Documents/Paradox Interactive/CK3/pdx_settings.txt .
From your Documents/Paradox Interactive/CK3/logs/ folder, attach here system.log , error.log , exceptions.txt