If you need a deeper dive into how the Steamworks API works, what a oneshot call does at the system call level, or a case study of a game where this error became widespread (e.g., Stardew Valley modding crashes), please specify, and I can expand accordingly.
if (!SteamAPI_Init()) // Log error, maybe retry after delay, but OneShot implies no retry. // Better to use SteamAPI_RestartAppIfNecessary() first. could not initialize steamworks api oneshot