V0401

Hydration state · thrown by @voltdev/core (server.ts)

A development build says:

the hydration state for "‹key›" could not be serialized: ‹cause›

The parts in ‹guillemets› are filled in from your program when it happens.

In a production build

The sentence above is not in a production bundle — it would cost every application the bytes of every message whether or not it ever failed. What a production build keeps is the code, what failed, and the link to this page, so the same error there reads:

[volt] V0401 key=‹key› https://voltjs.dev/e/V0401

and carries code ('V0401') and detail ({ key }) as fields, so a reporter can group by them without reading the text. See Errors for how an error is shaped, and the diagnostics option of the Vite plugin for a build that wants only the code.

Every error code