application exception

0xC0000409 STACK_BUFFER_OVERRUN / FAST_FAIL

The program detected its own memory safety was compromised and shut down on purpose. Despite the scary mechanism, for you it's simply a program bug — Windows is protecting you from continuing in a bad state.

What to do about it

Update the program.
Disable plugins/mods/overlays as a test.
Report to the developer with the faulting module from the report.

Where you will see this

Windows Error Reporting writes this code into Report.wer files and app-crash minidumps when a program dies but Windows itself stays up. It is not a blue-screen stop code — for those see the stop-code library.

See which module threw this exception

Drop the program's .wer report or crash dump into the app-crash reader — the faulting module is usually the real story. Parsed locally.

Open the app-crash reader →