application exception

0xC0000420 ASSERTION_FAILURE

The program hit an internal assert and chose to die rather than continue with bad state. Developer-facing, but for you it still means: update, strip plugins, report with the module name.

What to do about it

Update to the newest build — asserts are often removed or fixed quickly.
Disable mods/plugins.
Include the faulting module when you file a bug 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 →