Google Apps Integration Issues "invalid_grant"

This week one customer reported an issue where their frevvo forms integrated with Google Apps (Sheets, Drive) stopped working. Yesterday our own frevvo Training Registration form which pulls back a list of available training classes from a Google Sheet suddenly failed to populate the class list dropdown from the sheet.

The frevvo Cloud server log files contained Google "invalid_grant" errors. The Google Accounts Connected Apps & Sites page where the frevvo app Oauth access token was created showed that frevvo Live Forms Cloud App had mysteriously gone missing.

The Google Account should look like this image below but instead it was missing the frevvo grant.

The solution is to create a new Google frevvo app access token and then update all your forms/flows that had used the old missing token with the new token. This means updating both the Google Sheets connection via the wizard and any business rules which used the token.

We do not yet know why Google automatically deleted the frevvo app access token in our customer's Google Account or in our own Google Account. We are still investigating.