How to Fix “File is Invalid” Private Key Error in Firebase Settings

Introduction

When updating Firebase settings in your backend, you may encounter the error:

There was a problem with the private key provided: File is invalid.

This happens if the Application ID (Android Package Name) in your backend doesn’t match the one in your Firebase project. This article explains how to resolve the mismatch and upload a valid configuration file.

Create a New Firebase Project

1. Go to https://console.firebase.google.com and click Add project.
2. Enter a project name and follow the prompts to create it.
3. In the project overview, click the Android icon to add a new Android app.
4. For Android package name, enter the exact Application ID/Package Name used in your backend.
5. Complete the registration steps.
   

Download the Configuration File

1. After registering your Android app, click Download google-services.json.
2. Save this file to your local machine—do not rename it.
   

Upload the New JSON File to the Backend

1. In your WordPress or plugin settings, locate the Firebase configuration section.
2. Click Upload (or Choose File) and select the downloaded google-services.json.
   
3. Click Save Changes to apply the new configuration.
   

Troubleshooting and FAQs

Q: The error persists after uploading the new file. What should I check?
A: Make sure the JSON file is valid (no extra characters) and its package_name field matches your backend’s Application ID exactly.

Q: Can I keep using my existing Firebase project?
A: Yes. Instead of a new project, you can add another Android app to your current project with the correct package name and download its JSON.

Q: What if I accidentally uploaded the wrong file again?
A: Simply repeat the Upload the New JSON File steps with the correct google-services.json.