Auto-Deployment Failing with "An unexpected error happened"

[xavierkahn]

Current vs Expected Behavior

Expected: Automatic deployments should trigger and complete successfully when pushing commits to GitHub.

Current: Deployments are being triggered and build successfully, but fail at the final “Deploying outputs…” step with an infrastructure error.

Problem Description

I’m experiencing deployment failures on my React project that was recently transferred from my brother’s Vercel account to mine. The builds complete successfully but fail during the final deployment step.

Error Details

[10:15:08.196] Build Completed in /vercel/output [18s]
[10:15:08.221] Deploying outputs…
[10:18:08.567] An unexpected error happened when running this build. We have been notified of the problem. This may be a transient error. If the problem persists, please contact Vercel Support Help

Build Process (Working Correctly)

The entire build process works perfectly:

• Repository cloning: github.com/kahnxa/runnonwebsite

• Dependencies installation: Completes in 2s

• React build: Compiles successfully in ~13s

• File generation: All static files created properly

• Fails only at: “Deploying outputs…” step

Code and Configuration

Repository: github.com/kahnxa/runnonwebsite

vercel.json:

{
“builds”: [
{
“src”: “package.json”,
“use”: “@vercel/static-build”,
“config”: { “distDir”: “build” }
}
],
“routes”: [
{ “handle”: “filesystem” },
{ “src”: “/(.*)”, “dest”: “/index.html” }
]
}

package.json build script:

{
“scripts”: {
“build”: “react-scripts build”
}
}

Project Information

• Framework: React (Create React App)

• Project transferred: From another Vercel account to mine

• Repository: Recently moved from runnon2025/runnonwebsite to kahnxa/runnonwebsite

• Build region: Washington, D.C., USA (East) – iad1

• Build machine: 2 cores, 8 GB

• Vercel CLI: 44.5.0

Steps to Reproduce

1. Make any commit to the repository

2. Push to GitHub (main branch or any branch)

3. Vercel automatically triggers deployment

4. Build completes successfully

5. Deployment fails at “Deploying outputs…” step

Additional Context

• Multiple deployment attempts result in the same error

• Manual deployments via CLI also fail with “Invalid JSON response”

• The issue started occurring after the project was transferred to my account

• Previous deployments (77+ days ago) worked fine before the transfer

Attempted Solutions

• Tried pushing to different branches

• Attempted empty commits to trigger redeployment

• Verified repository access and permissions

• Confirmed build process works locally

The error message indicates this is likely a Vercel infrastructure issue, but it’s been consistent across multiple deployment attempts over several hours.

[xavierkahn]

Fixed by entering my email into the config file.