Why am I getting an 'FCM registration error: Failed to retrieve token' in my Unity Android build?

This error message typically indicates a configuration issue within your Unity project, even if your Firebase and Pushwoosh dashboards seem correct. The most common cause is the misplacement of the google-services.json file.

Follow these steps to resolve the issue:

1. Check the google-services.json File Location

   Firebase requires this file to be in a specific location to initialize correctly. Ensure you have placed the google-services.json file (downloaded from your Firebase project) directly into the root of your Assets folder within your Unity project.

   • Incorrect Path Example: YourProject/Assets/Plugins/google-services.json
   • Correct Path: YourProject/Assets/google-services.json

2. Verify AndroidManifest.xml Configuration

   An improperly configured AndroidManifest.xml can also lead to registration failures, sometimes showing a 401 Unauthorized error in the device logs. Verify that your Pushwoosh API token is correctly added to your main AndroidManifest.xml file.

   <application>
       <!-- other tags -->
       <meta-data android:name="com.pushwoosh.apitoken" android:value="YOUR_PUSHWOOSH_API_TOKEN" />
       <!-- other tags -->
   </application>
   

   If you have multiple AndroidManifest.xml files in your project (e.g., from different plugins), ensure this meta-data tag is present in the final, merged manifest used for the build.

Correcting the location of the google-services.json file resolves the vast majority of these token retrieval errors.