ERROR_BAD_SERVICE_ENTRYPOINT

{Invalid Service Callback Entrypoint} The %hs service is not written correctly.

Matched as: the code as given (hex)

{Invalid Service Callback Entrypoint} The %hs service is not written correctly. The stack pointer has been left in an inconsistent state. The callback entrypoint should be declared as WINAPI or STDCALL. Selecting OK will cause the service to continue operation. However, the service process may operate incorrectly.

Source: System Error Codes (500-999) - Win32 apps · CC-BY-4.0 (MicrosoftDocs/sdk-api, repo license verified 2026-10-09) · retrieved 2026-10-09