sveltejs/kit · error · HandledHttpError

${prerendered.error}

Error message

${prerendered.error}

What it means

During prerendering, remote functions first look up a prerendered response cache entry. If that entry is of type 'error', the stored error is re-thrown as a HandledHttpError with the prerendered error's original message, reproducing the failure that was captured when the page was prerendered.

Solutions

1. Fix the root error the remote function threw during prerendering (check build logs for the original failure)
2. Delete the .svelte-kit/build output and re-prerender so the error entry is regenerated
3. Guard the remote call with a fallback so it does not fail during prerender
4. Ensure required env vars/secrets are available at build time

Example fix

// before: prerendered page captured a failing query
export const load = async () => ({ posts: await getPosts() }); // fails at build if API down
// after
import { prerender } from '$app/server';
export const load = async () => {
  try {
    return { posts: await getPosts() };
  } catch {
    return { posts: [] };
  }
};

null

null

try {
  return await myQuery(arg);
} catch (e) {
  return fallbackValue; // don't let prerendered error entries propagate
}

When it happens

Trigger: A remote function is invoked during runtime (or prerender fallback) and finds a prerendered cache entry whose type is 'error' — i.e. the remote call failed when the page was originally prerendered and that failure was serialized into the prerender manifest.

Common situations: Deploying prerendered pages whose remote query/command failed at build time (expired tokens, missing env vars at build); stale .svelte-kit output after an API change; a prerendered page snapshotting an intermittent backend failure.

Related errors

• Cannot call ' .withOverride()' on the server
• Cannot call query.batch
• Cannot call query ' ' while prerendering, as prerendered…
• A form object can only be attached to a single
• `asset(' ')` should now be `asset(' ')

AI-assisted analysis of sveltejs/kit@03f1687fe6 (2026-09-02). Data as JSON: /api/errors/16e779c4c0371ad2. Report an issue: GitHub.

Appendix: source

Thrown at packages/kit/src/runtime/app/server/remote/prerender.js:116

				/** @type {RemoteFunctionResponse | undefined} */
				let prerendered;

				try {
					// TODO adapters can provide prerendered data more efficiently than
					// fetching from the public internet
					// `request.url` rather than `event.url`, which throws inside queries
					const response = await fetch(new URL(url, event.request.url).href);

					if (response.ok) {
						prerendered = /** @type {RemoteFunctionResponse} */ (await response.json());
					}
				} catch {
					// not available prerendered, fallback to normal function
				}

				if (prerendered) {
					if (prerendered.type === 'error') {
						throw new HandledHttpError(prerendered.error);
					}

					return parse(prerendered.data)._;
				}
			}

			// during a prerender run, the same function might be invoked while rendering
			// multiple pages — share the result across the entire run
			if (state.prerendering?.remote_responses.has(url)) {
				return /** @type {Promise<any>} */ (state.prerendering.remote_responses.get(url));
			}

			const promise = run_remote_function(
				event,
				{ ...state, is_in_remote_prerender: true },
				false,
				() => validate(arg),
				fn

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