App Router build fails with “Expected workUnitAsyncStorage to have a store” when prerendering /dashboard and /_not-found (Next 16.0.8 + Turbopack)

[Nalcakars]

Hi everyone,
I’m consistently getting a prerendering crash during production build with Next.js 16.0.8 (Turbopack) — the build stops with:

Error occurred prerendering page "/dashboard". Read more: https://nextjs.org/docs/messages/prerender-error Error occurred prerendering page "/_not-found". Read more: https://nextjs.org/docs/messages/prerender-error Error [InvariantError]: Invariant: Expected workUnitAsyncStorage to have a store. This is a bug in Next.js. at K (C:\apps\happsbi-dashboard\.next\server\chunks\ssr\[root-of-the-server]__092ddb26._.js:1:83546) at br (C:\apps\happsbi-dashboard\.next\server\chunks\ssr\[root-of-the-server]__092ddb26._.js:4:7769) Export encountered an error on /dashboard/page: /dashboard, exiting the build. Export encountered an error on /_not-found/page: /_not-found, exiting the build.

It clearly says “This is a bug in Next.js”, and looks related to async context inside prerender / PPR / dynamic IO.

npm run dev works perfectly — no runtime errors.

npm run build fails consistently during prerendering.

Errors alternate between /_global-error, /_not-found, and /dashboard/reports/....

I already tried all known workarounds:

Added export const dynamic = 'force-dynamic' and fetchCache = 'force-no-store' to root layout.

Added custom app/not-found.tsx and app/global-error.tsx (with 'use client').

Split dashboard page into a server + client component (page.tsx + DashboardClient.tsx).

Verified that no headers(), cookies(), useRouter(), usePathname(), etc. are called from server components.

Despite this, the build still fails with the same InvariantError.

I'm waiting for your support, thank you

Additional information

Environment

Next.js: 16.0.8 (Turbopack)

Node.js: 20.x (Windows)

Framework: App Router

Frontend stack: Mantine + TypeScript + React 19

Build command: npm run build

OS: Windows Server 2019 (PowerShell terminal)

Example

No response

[icyJoseph]

Please try to build with npx next build --debug-prerender that one outputs a lot more info

[Nalcakars]

thanks again for the pointers,

I tried the command you suggested,

`⚠ Prerendering is running in debug mode. Note: This may affect performance and should not be used for production.
▲ Next.js 16.0.8 (Turbopack)

• Environments: .env.local, .env.production

Creating an optimized production build ...
✓ Compiled successfully in 4.2s
✓ Finished TypeScript in 5.3s
✓ Collecting page data using 23 workers in 652.7ms

Error occurred prerendering page "/global-error". Read more: https://nextjs.org/docs/messages/prerender-error
C:\apps\happsbi-dashboard\node_modules\next\dist\server\app-render\work-unit-async-storage.external.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\apps\happsbi-dashboard.next\server\chunks\ssr[root-of-the-server]__092ddb26..js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\Apps\happsbi-dashboard\node_modules\next\dist\compiled\next-server\app-page-turbo.runtime.prod.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\Apps\happsbi-dashboard\node_modules\next\dist\server\lib\trace\tracer.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\Apps\happsbi-dashboard\node_modules\next\dist\export\routes\app-page.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\Apps\happsbi-dashboard\node_modules\next\dist\trace\trace.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\Apps\happsbi-dashboard\node_modules\next\dist\export\worker.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
Error [InvariantError]: Invariant: Expected workUnitAsyncStorage to have a store. This is a bug in Next.js.
at createServerSearchParamsForServerPage (C:\apps\happsbi-dashboard.next\server\chunks\ssr[root-of-the-server]__092ddb26..js:6334:82)
at createMetadataComponents (C:\apps\happsbi-dashboard.next\server\chunks\ssr[root-of-the-server]__092ddb26..js:9609:26)

Export encountered errors on following paths:
/_global-error/page: /_global-error
`

So even when I focus only on app/page.tsx with --debug-build-paths, the build still dies while prerendering /_global-error, with the same workUnitAsyncStorage invariant.

This is not a monorepo – it’s a single Next app, no separate packages feeding components into app/.

[icyJoseph]

MMm wild, this also used --debug-prerender too right?

There's an issue when building, that in exchange for speed, it drops some info, that's why --debug-prerender was created. Whether or not that should be the case, and --debug-prerender benefits should be in build directly, is another discussion topic.

But long story, short, a failure in a page, ends up reflecting in one of those fallback files instead. Anyway.

I think the sourceMap error is likely caused by the attempt at showing a better error stack via --debug-prerender.

I wonder if the issue is in the root layout, somehow... Are you using a custom server? At this point I'd start to remove components from root layout.tsx and page.tsx, until I get a good build. The single path command build should speed things up.

[Nalcakars]

I temporarily replaced my app/layout.tsx with a fully minimal layout (no Mantine, no providers, no global styles, just html/body):

export const dynamic = 'force-dynamic';
export const fetchCache = 'force-no-store';

export default function RootLayout({ children }: { children: React.ReactNode }) {
  return (
    <html lang="tr">
      <body>{children}</body>
    </html>
  );
} 

Then I ran:

npx next build --debug-build-paths="app/page.tsx" --debug-prerender

result:

⚠ Prerendering is running in debug mode. Note: This may affect performance and should not be used for production.
▲ Next.js 16.0.8 (Turbopack)
- Environments: .env.local, .env.production

Creating an optimized production build ...
✓ Compiled successfully in 3.5s
✓ Finished TypeScript in 4.9s
✓ Collecting page data using 23 workers in 679.8ms

Error occurred prerendering page "/_global-error". Read more: https://nextjs.org/docs/messages/prerender-error
C:\apps\happsbi-dashboard\node_modules\next\dist\server\app-render\work-unit-async-storage.external.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\apps\happsbi-dashboard\.next\server\chunks\ssr\[root-of-the-server]__092ddb26._.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\Apps\happsbi-dashboard\node_modules\next\dist\compiled\next-server\app-page-turbo.runtime.prod.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\Apps\happsbi-dashboard\node_modules\next\dist\server\lib\trace\tracer.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\Apps\happsbi-dashboard\node_modules\next\dist\export\routes\app-page.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\Apps\happsbi-dashboard\node_modules\next\dist\trace\trace.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
C:\Apps\happsbi-dashboard\node_modules\next\dist\export\worker.js: Invalid source map. Only conformant source maps can be used to find the original code. Cause: Error: sourceMapURL could not be parsed
Error [InvariantError]: Invariant: Expected workUnitAsyncStorage to have a store. This is a bug in Next.js.
    at createServerSearchParamsForServerPage (C:\apps\happsbi-dashboard\.next\server\chunks\ssr\[root-of-the-server]__092ddb26._.js:6334:82)
    at createMetadataComponents (C:\apps\happsbi-dashboard\.next\server\chunks\ssr\[root-of-the-server]__092ddb26._.js:9609:26)

> Export encountered errors on following paths:
        /_global-error/page: /_global-error

the fact that the issue persists with a minimal root layout makes me think this might be an internal bug in how _global-error prerendering + workUnitAsyncStorage is wired.

[icyJoseph]

May I see a print of your app file tree?

[icyJoseph]

Why are you using, does removing them bring about more issues, or perhaps unwanted implicit behavior?

export const dynamic = 'force-dynamic';
export const fetchCache = 'force-no-store';

[drazenbebic]

I have the exact same issue. What's weird is that I thought it had to do something with some changes I made, so I reverted to my last commit which successfully built and deployed with Vercel, but I'm getting the same error there as well!

I'm using:

• Next.js 16.0.10
• React 19.2.3
• next-intl 4.6.0
• App Router

So, the exact error message with next build --debug-prerender:

 ⚠ Prerendering is running in debug mode. Note: This may affect performance and should not be used for production.
   ▲ Next.js 16.0.10 (Turbopack)
   - Environments: .env.local
   - Experiments (use with caution):
     ⨯ prerenderEarlyExit (disabled by `--debug-prerender`)
     ✓ serverSourceMaps (enabled by `--debug-prerender`)
     ⨯ turbopackMinify (disabled by `--debug-prerender`)

   Creating an optimized production build ...
 ✓ Compiled successfully in 12.7s
 ✓ Finished TypeScript in 3.1s    
 ✓ Collecting page data using 7 workers in 619.4ms    
Error occurred prerendering page "/_global-error". Read more: https://nextjs.org/docs/messages/prerender-error
Error [InvariantError]: Invariant: Expected workUnitAsyncStorage to have a store. This is a bug in Next.js.
    at ignore-listed frames
Error occurred prerendering page "/_not-found". Read more: https://nextjs.org/docs/messages/prerender-error
Error [InvariantError]: Invariant: Expected workUnitAsyncStorage to have a store. This is a bug in Next.js.
    at ignore-listed frames
Error occurred prerendering page "/de". Read more: https://nextjs.org/docs/messages/prerender-error
Error [InvariantError]: Invariant: Expected workUnitAsyncStorage to have a store. This is a bug in Next.js.
    at ignore-listed frames
Error occurred prerendering page "/hr". Read more: https://nextjs.org/docs/messages/prerender-error
Error [InvariantError]: Invariant: Expected workUnitAsyncStorage to have a store. This is a bug in Next.js.
    at ignore-listed frames
Error occurred prerendering page "/sr". Read more: https://nextjs.org/docs/messages/prerender-error
Error [InvariantError]: Invariant: Expected workUnitAsyncStorage to have a store. This is a bug in Next.js.
    at ignore-listed frames
Error occurred prerendering page "/bs". Read more: https://nextjs.org/docs/messages/prerender-error
Error [InvariantError]: Invariant: Expected workUnitAsyncStorage to have a store. This is a bug in Next.js.
    at ignore-listed frames
Error occurred prerendering page "/en". Read more: https://nextjs.org/docs/messages/prerender-error
Error [InvariantError]: Invariant: Expected workUnitAsyncStorage to have a store. This is a bug in Next.js.
    at ignore-listed frames

> Export encountered errors on following paths:
        /[locale]/page: /bs
        /[locale]/page: /de
        /[locale]/page: /en
        /[locale]/page: /hr
        /[locale]/page: /sr
        /_global-error/page: /_global-error
        /_not-found/page: /_not-found

My layout.tsx is located in src/app/[locale]/layout.tsx. I have no layout.tsx in src/app and adding one doesn't help. The file itself looks like this:

import React, { use } from 'react';
import { Analytics } from '@vercel/analytics/react';
import { SpeedInsights } from '@vercel/speed-insights/react';
import '../globals.css';
import { setRequestLocale } from 'next-intl/server';
import { locales } from '@/i18n/locales';
import { Footer, Header } from '@/components';
import { NextIntlClientProvider, useMessages } from 'next-intl';
import { Comfortaa, Inter } from 'next/font/google';
import { Metadata } from 'next';
import cn from 'classnames';
import StoryblokProvider from '@/components/storyblok-provider';

const comfortaa = Comfortaa({
  display: 'swap',
  subsets: ['latin'],
  weight: ['300', '400', '500', '600', '700'],
  preload: true,
  variable: '--font-heading',
});

const inter = Inter({
  display: 'swap',
  subsets: ['latin'],
  weight: ['400', '500', '600', '700', '800', '900'],
  preload: true,
  variable: '--font-copy',
});

export function generateStaticParams() {
  return locales.map(locale => ({ locale }));
}

export const metadata: Metadata = {
  icons: {
    icon: [
      {
        url: '/favicon.png',
        href: '/favicon.png',
      },
    ],
  },
};

const RootLayout = ({
  children,
  params,
}: Readonly<{
  children: React.ReactNode;
  params: Promise<{
    locale: string;
  }>;
}>) => {
  const { locale } = use(params);

  setRequestLocale(locale);

  const messages = useMessages();

  return (
    <StoryblokProvider>
      <html lang={locale} className={cn(inter.variable, comfortaa.variable)}>
        <body className="relative bg-neutral-100 flex flex-col w-full min-h-screen ">
          <NextIntlClientProvider locale={locale} messages={messages}>
            <Header />
            {children}
            <Footer />
          </NextIntlClientProvider>
        </body>
        <Analytics />
        <SpeedInsights />
      </html>
    </StoryblokProvider>
  );
};

export default RootLayout;

I'm really not sure what to do anymore. Any help would be massively appreciated.

[icyJoseph]

Node.js version? Mmm do these locale pages use the cookies function? or other next.js server side data? Feels like the core issue within the pages, upon failure the global-error is tried, but that also wrecks out and so does the not-found...

I remember an issue where the globa-not-found had missed NextIntlClientProvider, but the error logs were different.

[drazenbebic]

It's working for me again, but this is extremely odd. I did two things:

1. I fixed a type error which is the original reason my builds were failing.
2. I checked Node.js and realized I'm running 24 locally, while Vercel has 20. So I bumped it to 24.

I pushed the type fix and... it's working! Only on Vercel though. Locally, I'm still getting the pre-render issue. It's worth knowing that the pre-render issue only happens locally. On Vercel the only reason the build was ever failing was the type error in TypeScript I mentioned earlier. When I fixed it I ran next build to test out my fix and got the pre-render issue and I've been focused on that ever since. But like I said, this doesn't seem to happen on Vercel, only locally.

I tried deleting the yarn.lock, node_modules, and .next folder multiple times, but that didn't do much.

Another thing worth knowing is that this is a monorepo with Turborepo. I thought that it maybe only worked because of some build cache but I checked the logs and saw this:

Running build in Washington, D.C., USA (East) – iad1
Build machine configuration: 4 cores, 8 GB
Cloning github.com/foo/bar (Branch: main, Commit: 3a6999c)
Cloning completed: 851.000ms
Skipping build cache since Node.js version changed from "20.x" to "24.x"
Running "vercel build"
Vercel CLI 50.0.1
> Detected Turbo. Adjusting default settings...
Running "install" command: `yarn install`...

So it was a "fresh" build. No clue what's going on locally.

[drazenbebic]

Okay so I fixed it locally by once again deleting all the node_modules folders (also inside other workspaces), the .next folder and running yarn cache clear.

Afterwards I ran yarn install and next build and it worked like nothing ever happened 🤷

[icyJoseph]

Well, it could've been duplicate Next.js versions running? I had not seen it manifest like this before though.