Is GAT+ failing to run? Check these options in your Admin Console

Click the Apps Launcher on the top right corner of your Chrome session and click on the Admin Icon:

Enter the Apps section:

Then click on the G Suite Marketplace apps.

Click on the GAT+ app.

You will need to click on the text Grant access and the status should be Granted and make sure GAT+ is Enabled for all organizational units.

To enable Classroom auditing

In the Google Apps Admin console, select Apps, G Suite, Settings for Classroom and Data Access. Make sure the option Users can authorize apps to access their Google Classroom data is enabled.