Recently Google has shifted their focus from Google+ to their "Google My Business" service. The changes they have implemented have added a prerequisite requirement for authenticating Google in all areas of our platform(Social Marketing Authentication, Google My Business Authentication in Reputation Management, or Listing Sync in Listing Builder). To allow for authentication, it is required that a Google+ profile be present upon the Google Account being authenticated.
A Google account is an all in one account for all Google services. However, since the change, when someone creates a new Google account, whether through “Google My Business” or as a personal account, they no longer get Google+ enabled upon the account by default. Luckily, these Google users can "upgrade" their account to include Google+. To upgrade, log into your Google Account and go to
>> https://plus.google.com/up/accounts/upgrade/ <<.
NOTE: either use a private browsing session to do this, or ensure you log out of your personal account, and log in with whatever account has management permissions for the page you are wanting to connect.
This will allow you to upgrade and gain access to Google+ for that account. Once this has been done, you will be able to authenticate this account within the Platform. You can learn how to authenticate social media profiles in this article. Also here is a video on Authenticating Google My Business in Reputation Management