sveltejs/kit · critical

${manifest_error.message ?? 'Invalid routes'}

Error message

${manifest_error.message ?? 'Invalid routes'}

What it means

In the Vite dev server, when evaluating the generated server manifest fails (e.g. the manifest module throws on import), SvelteKit returns a 500 HTML error page to the browser with the thrown error's message, or the fallback text 'Invalid routes'. It means SvelteKit could not build/parse the route manifest for dev mode, so no routes can be served.

Source

Thrown at packages/kit/src/exports/vite/dev/index.js:417

				const request = (svelte_config.adapter?.vite?.getRequest ?? getRequest)({
					base,
					request: req,
					response: res
				});

				if (manifest_error) {
					console.error(styleText(['bold', 'red'], manifest_error.message));

					const error_page = load_error_page(svelte_config);

					/** @param {{ status: number; message: string }} opts */
					const error_template = ({ status, message }) => {
						return error_page
							.replace(/%sveltekit\.status%/g, String(status))
							.replace(/%sveltekit\.error\.message%/g, escape_html(message));
					};

					res.writeHead(500, {
						'Content-Type': 'text/html; charset=utf-8'
					});
					res.end(
						error_template({ status: 500, message: manifest_error.message ?? 'Invalid routes' })
					);

					return;
				}

				const rendered = await server.respond(request, {
					getClientAddress: () => {
						const { remoteAddress } = req.socket;
						if (remoteAddress) return remoteAddress;
						throw new Error('Could not determine clientAddress');
					},
					read: (file) => {
						if (file in manifest.server_assets) {
							return fs.readFileSync(from_fs(file));

View on GitHub (pinned to 03f1687fe6)

Solutions

1. Read the underlying manifest_error stack trace printed in the terminal to find the real cause.
2. Check all route files under src/routes for invalid filenames or syntax errors.
3. Delete node_modules/.vite and restart the dev server to clear stale cache.
4. Verify svelte.config.js and plugin versions match (svelte, @sveltejs/kit, vite).

Example fix

// before: broken route file src/routes/[slug/[nested/page.svelte
// after: fix the invalid route segment nesting or rename the file
src/routes/[slug]/[nested]/page.svelte

// before dev: sanity check route files exist and config parses
import { readFileSync } from 'node:fs';
const cfg = readFileSync('svelte.config.js', 'utf8');
if (!cfg) throw new Error('missing svelte.config.js');

When it happens

Trigger: Running `vite dev` when the server manifest module (src/manifest.js) throws during import — typically a syntax/runtime error in generated manifest code, an invalid +page/+server file that breaks route parsing, or a plugin corrupting the manifest.

Common situations: Malformed route file names, a broken svelte.config.js, incompatibilities after upgrading SvelteKit/Vite, or a custom Vite plugin that patches the manifest incorrectly; the browser shows a 500 page saying 'Invalid routes'.

Related errors

• The configured Vite SSR environment must be a RunnableDevEnv
• The ${route.id} and ${existing.route_id} routes must be merg
• @sveltejs/enhanced-img requires @sveltejs/vite-plugin-svelte
• Could not locate ${file_path}. Please move it to be located
• Could not locate ${file_path}. See https://vitejs.dev/guide/

AI-assisted analysis of sveltejs/kit@03f1687fe6 (2026-09-02). Data as JSON: /api/errors/048243b046705bca. Report an issue: GitHub.