Nuxt/Vue App Stopped Deploying Sep-23-2025 with error message: !!! CustomerError: We failed to validate the deploy-manifest.json file found in your build output directory

Thanks AI - but no dice :(

I have "resolved" this issue for the time being by doing the following:

1. Download the artifacts of a successful deployment
2. Copy the deploy-manifest.json file from that .zip file into the root directory of my web app in version control
3. Edit the json file to update the computeResources value from "runtime": "nodejs18.x" to "runtime": "nodejs20.x"
4. Commit that file
5. Edit the amplify.yml configuration in the AWS Amplify console for my App and include the following:

    build:
      commands:
         . . .
        - yarn run build
        - mkdir -p .amplify-hosting
        - cp deploy-manifest.json .amplify-hosting/deploy-manifest.json 

With these completed, my deployments went back to succeeding.

¯_(ツ)_/¯

The deploy-manifest.json file is generated by the nitro aws-amplify preset bundled within Nuxt.
Even if it’s not explicitly defined under nitro in nuxt.config.ts, it will still be automatically applied when building with Amplify.
However, the older version of the Nitro preset bundled with older versions of Nuxt is fixed to nodejs18.x.

https://github.com/nitrojs/nitro/commit/d03863441b6811150281b9944755b32af91ee0e0

By updating Nuxt, the default will switch to nodejs20.x, and you’ll also be able to specify the runtime version as an option.

In other words, simply updating Nuxt should make the deployment succeed.

Im experiencing the same issue. And I tried many things without any success yet. I tried this at nuxt.config.ts

		nitro: {
			preset: 'aws-amplify',
			awsAmplify: {
				runtime: "nodejs20.x"
			},
		},

Also this at amplify.yml

version: 1
settings:
  nodeVersion: "20"
applications:
  - appRoot: apps/nuxt

And my package.json also

	"engines": {
		"node": ">=20.0.0"
	}

If I build locally my build-manifest.json looks ok

  "computeResources": [
    {
      "name": "default",
      "entrypoint": "server.js",
      "runtime": "nodejs20.x"
    }
  ],

It appears that AWS Amplify has implemented stricter validation for Node.js runtime versions on September 23, 2025, following their previously announced end of support for Node.js 18 (which was scheduled for September 15, 2025).

The error message indicates that even though you've set Node.js 20.11.0 for your build environment through "Live Package Updates," there's still a reference to nodejs18.x in a deploy-manifest.json file that Amplify is generating during the deployment process.

This is likely happening because your Nuxt application's SSR (Server-Side Rendering) configuration is still referencing Node.js 18 for the runtime environment, even though your build environment is using Node.js 20.

To fix this issue, you need to explicitly specify the Node.js version for both build and runtime environments in your Amplify configuration. You can do this by:

1. Adding or updating the nodeVersion setting in your amplify.yml file:

settings:
nodeVersion: "20"

2. If you're using the Nuxt framework adapter for Amplify, make sure it's configured to use Node.js 20 for the server runtime.

3. For Nuxt applications, you might also need to specify the Node.js version in your package.json:

"engines": {
"node": ">=20.0.0"
}

The issue is that while your build is successfully completing with Node.js 20, the server-side rendering component is still being configured to use Node.js 18, which is no longer supported by Amplify as of September 15, 2025.
Sources
my amplify deploy app problem | AWS re:Post
How to identify Nodejs version being use for Amplify app using Next.js - SSR Framework | AWS re:Post