Missing export -- import ReactDOMServer from "react-dom/server";

[aman-coder28]

Which project does this relate to?

Router

Describe the bug

I have been trying the new RSC feature in Tanstack Start, its great in dev mode, but built failed saying -

"default" is not exported by "node_modules/react-dom/server.react-server.js"
[ node_modules/@tanstack/react-router/dist/esm/ssr/renderRouterToStream.js:2:8 ]
import ReactDOMServer from "react-dom/server";
───────┬──────
╰──────── Missing export

i have gone a head and searched node_modules in tanstack router file and searched online, what i found is react-dom/server doesn't have a default export, as its used in tanstack router files

router/packages/react-router/src/ssr/renderRouterToStream.tsx

Line 2 in c857087

import ReactDOMServer from 'react-dom/server'

and

router/packages/react-router/src/ssr/renderRouterToString.tsx

Line 1 in c857087

import ReactDOMServer from 'react-dom/server'

Your Example Website or App

https://github.com/TanStack/router/tree/main/examples/react/start-rscs

Steps to Reproduce the Bug or Issue

1. create a new tanstack start app
2. add @vitejs/plugin-rsc plugin
3. configure vite config

import { tanstackStart } from "@tanstack/react-start/plugin/vite";
import viteReact from "@vitejs/plugin-react";
import rsc from "@vitejs/plugin-rsc";
import { defineConfig } from "vite";

const config = defineConfig({
	plugins: [
		tanstackStart({
			rsc: {
				enabled: true,
			},
		}),
		rsc(),
		viteReact(),
	],
	resolve: {
		tsconfigPaths: true,
	},
});

export default config;

5. build the app

### Expected behavior

build failing saying

[MISSING_EXPORT] Error: "default" is not exported by "node_modules/react-dom/server.react-server.js".
   ╭─[ node_modules/@tanstack/react-router/dist/esm/ssr/renderRouterToString.js:1:8 ]
   │
 1 │ import ReactDOMServer from "react-dom/server";
   │        ───────┬──────
   │               ╰──────── Missing export
───╯

[MISSING_EXPORT] Error: "default" is not exported by "node_modules/react-dom/server.react-server.js".
   ╭─[ node_modules/@tanstack/react-router/dist/esm/ssr/renderRouterToStream.js:2:8 ]
   │
 2 │ import ReactDOMServer from "react-dom/server";
   │        ───────┬──────
   │               ╰──────── Missing export

### Screenshots or Videos

<img width="1061" height="380" alt="Image" src="https://github.com/user-attachments/assets/30d0ad90-8443-4552-bcc0-e90fa1684f16" />

### Platform

- Router / Start Version: "@tanstack/react-start": "^1.167.34", "@tanstack/react-router": "^1.168.19"
- OS: Linux (EndeavourOS)
- Browser: helium browser  0.11.1.1
- Browser Version: 147.0.7727.55 
- Bundler:  vite
- Bundler Version: 8.0.8


### Additional context

 the fix might be like

```js
import * as ReactDOMServer from "react-dom/server";

[schiller-manuel]

please check if this fixes it: https://github.com/TanStack/router/releases/tag/release-2026-04-13-2111

if not, please provide a complete minimal reproducer project as a git repo

[aman-coder28]

yes, now build process is finishing successfully in my machine and in vercel build, Thank.