First of all, there are four types of role in Facebook Developer console:

Administrator Developer Testers Analytics Users

However, only administrators, developers and testers are permitted to test Facebook Login feature during the development stage. People not in these categories would fail with below error:

Android Studio Error Log:

E/fb4a.GraphServiceQueryExecutor: query error

Application screenshot:

Screen captured from Android version

Error performing query is not a clear message to either user or developer. After doing some research, the root cause is that the user is not a registered tester in the Facebook Developer Console. See below steps to add him as a tester:

Step 1: Find tester’s Facebook username

First of all, make sure you understand the difference between username and name in Facebook world.

1. username is the unique identifier to represent your profile. It is also a part of the url path directing to your Facebook page.

2. name is the display name of your Facebook account and does not have to be unique.

You have to find tester’s username by simply going to his Facebook page and copy everything after https://www.facebook.com/ .

Step 2: Adding his Facebook account to the tester list

You (administrator) have to go to the Facebook Developer Console and navigate to the Roles tab from the left side menu. Then click Add Testers button at the Testers session:

Followed by entering the username found in step 1:

After successfully inviting tester, the tester list would be updated as below:

Updated “Testers” list

Step 3: Ask tester to accept the invitation of being a tester

There would be an invitation sent to the tester’s Facebook account. The tester can view the invitation by viewing his notification at the Facebook page.

Tester has to accept the invitation and register as a Facebook Developer first.

The registration of Facebook developer is simple and just requires your phone number.