Runtime Error Error from Companion: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference

I wanted to create an app with firebaseDB as a database.
Here's what I did:
Firebase Account:
Realtime Database>> Create DB >> Chosen Test Mode
Under rules, I set the read and write to true

On project Settings>>Service Accounts>>Database secrets - Copied the secrets for FirebaseToken

On mit app inventor, I only use the following components
Screenshot 2025-09-02 142513

I changed my FirebaseURL and token from the new firebase project I have created. Right when the project loads on MIT app companion, I encountered this error.

I'm using Android for my App companion, version 2.76
Tried to clear data and cache on app, created a fresh new project but same error persists even if I did not put any blocks yet.

I have tried the "do it" option and this is the result

Error from Companion: Attempt to invoke virtual method 'com.firebase.client.Firebase com.firebase.client.Firebase.child(java.lang.String)' on a null object reference

It seems Missing or Incorrect Firebase Properties, You have not correctly set the Firebase URL and/or the Project Bucket in the Firebase component's properties in the Designer view. If these are left blank or have an invalid value, the component cannot connect to your database, and the object remains null.

Update:
It just doesn't make any sense :face_with_spiral_eyes:

I tried creating a new project on different account, using the same firebase credentials and it worked.
As I have observed, first account (the one which does not work) , every time I add a firebaseDB component, it won't provide a default firebase token and would instantly provide an error.

2nd account(which works), every time I add a firebaseDB component, it will provide its own default FirebaseToken. It still worked even if I already removed the firebaseToken. (retained the same firebaseURL)

  1. Ensure your Firebase Project is on the us-central server. Other locations will not work with the Firebase component.
  2. You do not need the api key or secret, you can leave the FirebaseToken box empty.
  3. The FirebaseUrl should end with a /
  4. Ensure that the projectBucket set in the desinger matches the projectBucket in your Firebase data.

Also see here:

I'm experiencing the same issue. My project is hosted on the us-central server, the Firebase URL ends with a /, and the project bucket is correct. I've tried everything, but I keep getting the following error:

Error from Companion: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference

This error occurs as soon as I connect to the AI Companion, even before adding any blocks.

Are you using the latest companion app ? 2.76 or 2.76u.

I am using the online version
image

Good, but what version companion app are you using?

Oh, I am using the 2.76 version

Check all screens for empty sockets in all blocks.

Not having any issues this end.

Have you tried:

Restart AppInventor
Restart Browser
Restart Computer