If you have a group license, you should check to be sure that API access is enabled for your domain in the Google Admin Console. This allows Read&Write for Google Chrome to check if a user is in your TexthelpReadWriteUsers group and gives them access to the premium features.
Group licenses were designed to use the Google Apps provisioning API to do this. Effective April 20, 2015, Google will no longer be providing this API. For more information from Google, please read Directory API: Getting Started
Because of this, Read&Write for Google Chrome now uses Google Apps Administrative APIs. This requires API access in the Google Admin Console to be enabled. API access is enabled by default.
To check that API access is enabled, log into your Google Admin Console and do the following:
1. Go to Security
2. Click API reference
3. Make sure that the Enable API access box is checked
If it’s unchecked, check the box and click Save Changes in the bottom right corner of the screen.
You can also watch a quick video tutorial.