For a more complete integration guide, see the Google Analytics ROI Integration Guide. This is step 5.
IMPORTANT: If your OAuth2 Token populated successfully, skip this step.
1. The fix to most Google Analytic issues within ROI involves resetting the OAuth2 Token. To refresh the token, log into your Gmail account associated with your ROI account.
2. Click the boxes icon in the upper right hand corner and select My Account. See the picture below.
3.Under Sign In and Security select Connected Apps & Sites.
4. Click on Manage Apps.
5. ROI should appear as an option (titled CLM). Click on it, then click Remove.
6. Make sure you are logged out of all other Google Accounts except for the one associated with ROI. Within ROI, navigate to Admin > Preferences > Google and click the OAuth2 button. The pop-up should appear granting permissions to ROI, and the code should populate in the field. Click Save.