Cloudflare Developers•2w ago

Uncaught ReferenceError: MessageChannel is not defined

Updating different (unrelated) dependencies causes this. At least some seem to be related to React19 (which itself also causes this 🥲 I'm not sure it's directly CF related tho it only happens on wrangler deploy and only after building etc 🤔

Total Upload: 20484.96 KiB / gzip: 3636.26 KiB

✘ [ERROR] A request to the Cloudflare API (/accounts/ddddc353374f7ec886d7d7d97e239a71/workers/scripts/rakkas-cf-origin/versions) failed.

  Uncaught ReferenceError: MessageChannel is not defined
    at null.<anonymous>
  (file://[..]/node_modules/.pnpm/[email protected][email protected]/node_modules/react-dom/cjs/react-dom-server.browser.production.js:126:15)
  in
  ../../node_modules/.pnpm/[email protected][email protected]/node_modules/react-dom/cjs/react-dom-server.browser.production.js
    at null.<anonymous> (entry-cf.js:32:50) in __require2
    at null.<anonymous>
  (file://[..]/node_modules/.pnpm/[email protected][email protected]/node_modules/react-dom/server.browser.js:6:7)
  in ../../node_modules/.pnpm/[email protected][email protected]/node_modules/react-dom/server.browser.js
    at null.<anonymous> (entry-cf.js:32:50) in __require2
    at null.<anonymous>
  (file://[..]/dist/edge/hattip.js:12:62)
  in dist/edge/hattip.js
    at null.<anonymous> (entry-cf.js:29:59) in __init
    at null.<anonymous>
  (file://[..]/dist/edge/entry-cf.js:2:1)
   [code: 10021]

Total Upload: 20484.96 KiB / gzip: 3636.26 KiB

✘ [ERROR] A request to the Cloudflare API (/accounts/ddddc353374f7ec886d7d7d97e239a71/workers/scripts/rakkas-cf-origin/versions) failed.

  Uncaught ReferenceError: MessageChannel is not defined
    at null.<anonymous>
  (file://[..]/node_modules/.pnpm/[email protected][email protected]/node_modules/react-dom/cjs/react-dom-server.browser.production.js:126:15)
  in
  ../../node_modules/.pnpm/[email protected][email protected]/node_modules/react-dom/cjs/react-dom-server.browser.production.js
    at null.<anonymous> (entry-cf.js:32:50) in __require2
    at null.<anonymous>
  (file://[..]/node_modules/.pnpm/[email protected][email protected]/node_modules/react-dom/server.browser.js:6:7)
  in ../../node_modules/.pnpm/[email protected][email protected]/node_modules/react-dom/server.browser.js
    at null.<anonymous> (entry-cf.js:32:50) in __require2
    at null.<anonymous>
  (file://[..]/dist/edge/hattip.js:12:62)
  in dist/edge/hattip.js
    at null.<anonymous> (entry-cf.js:29:59) in __init
    at null.<anonymous>
  (file://[..]/dist/edge/entry-cf.js:2:1)
   [code: 10021]

Update: nodejs_compat is already enabled in my wrangler.toml

9 Replies

Rohan Vashisht•6d ago

Hello! Same issue here

[wrangler:inf] Ready on http://localhost:8788
⎔ Starting local server...
✘ [ERROR] service core:user:zigistry: Uncaught ReferenceError: MessageChannel is not defined

    at null.<anonymous> (g9werpoqfas.js:9183:18) in requireReactDomServer_browser_production
    at null.<anonymous> (g9werpoqfas.js:13866:9) in requireServer_browser
    at null.<anonymous> (g9werpoqfas.js:14087:29) in
  .wrangler/tmp/pages-vjhWro/chunks/_@astro-renderers_Du4IiIVl.mjs
    at null.<anonymous> (g9werpoqfas.js:18:59) in __init
    at null.<anonymous> (g9werpoqfas.js:43883:1)



✘ [ERROR] The Workers runtime failed to start. There is likely additional logging output above.

[wrangler:inf] Ready on http://localhost:8788
⎔ Starting local server...
✘ [ERROR] service core:user:zigistry: Uncaught ReferenceError: MessageChannel is not defined

    at null.<anonymous> (g9werpoqfas.js:9183:18) in requireReactDomServer_browser_production
    at null.<anonymous> (g9werpoqfas.js:13866:9) in requireServer_browser
    at null.<anonymous> (g9werpoqfas.js:14087:29) in
  .wrangler/tmp/pages-vjhWro/chunks/_@astro-renderers_Du4IiIVl.mjs
    at null.<anonymous> (g9werpoqfas.js:18:59) in __init
    at null.<anonymous> (g9werpoqfas.js:43883:1)



✘ [ERROR] The Workers runtime failed to start. There is likely additional logging output above.

I am using pages and workers, I am getting this same issue Are you using astro? or just apis? An easy fix: just take your package.json to the previous configuration when it was working 🤣 And it really worked but, do this at your own risk, because using unupdated packages is generally considered a security vulnerability Anyways, I ain't from cloudflare, I am just someone like you getting errors and trying to fix them, lets wait for someone from cloudflare to reply

CanRauOP•6d ago

Yea this is working for me for now as well, it started to happen only with react 19, all other packages on latest, now it seems like as packages start to officially support react 19 they cause the same issue so now I have lots of outdated packages 🥲 Surprising that seemingly no one else seems to run into this so far 🤔

Radoš•5d ago

the code throwing error

// react-dom-server.browser.production.js
var channel = new MessageChannel(), taskQueue = [];
channel.port1.onmessage = function() {
    var task = taskQueue.shift();
    task && task();
};
function scheduleWork(callback) {
    taskQueue.push(callback);
    channel.port2.postMessage(null);
}

// react-dom-server.browser.production.js
var channel = new MessageChannel(), taskQueue = [];
channel.port1.onmessage = function() {
    var task = taskQueue.shift();
    task && task();
};
function scheduleWork(callback) {
    taskQueue.push(callback);
    channel.port2.postMessage(null);
}

Radoš•5d ago

https://github.com/facebook/react/issues/31827

GitHub

Bug: Uncaught ReferenceError: MessageChannel is not defined · Issue...

React version: 19.0.0 Steps To Reproduce Create an Astro & React project with server adapter for Cloudflare Try to deploy to Cloudflare Pages via wrangler deploy The current behavior Uncaught R...

CanRauOP•5d ago

nice, thank you for finding and reporting 🙏

jado•9h ago

Would love a solution to this! It looks like someone else hit the unsupported MessageChannel API in Vercel's Edge Runtime https://github.com/vercel/next.js/issues/60337 but this is the only issue I can find & it was never resolved, so they might still not support it. Not sure if this is in the scope for workerd or if React should revert its usage.

GitHub

Next.js 14.0.4 - Edge Runtime Warnings in scheduler Module · Issue ...

Link to the code that reproduces this issue https://github.com/Soheiljafarnejad/sabzlearn-front To Reproduce I am encountering warnings related to the use of Node.js APIs in the scheduler module wh...

jado•9h ago

@Mike Nomitch | Workers PM hi 👋 would opening an issue on workerd be appropriate for this?

Radoš•4h ago

@jado I think it is the React issue as MessageChannel is for the browsers only (or browser context).

jado•4h ago

mm i see

Gaming

Programming

Uncaught ReferenceError: MessageChannel is not defined