Unsure on how to solve a "termsOfServiceNotAccepted" Error - google-app-engine

Question

Background:
So I'm a novice to the whole app engine thing: I have made an app on google app engine that on the main page accepts user input and then sends the information to a handler that then uses the Big Query API to run a synchronous query with some tables I have uploaded to Big Query. The handler then sends back the results of the query as a json.
Problem:
In deployment it works mostly except sometimes a user can often run into this error while trying to make the synchronous query:
Error in runSyncQuery:
{
"error": {
"errors": [
{
"domain": "global",
"reason": "termsOfServiceNotAccepted",
"message": "BigQuery Terms of Service have not been accepted"
}
],
"code": 403,
"message": "BigQuery Terms of Service have not been accepted"
}
}
After doing some searching I com across this:
https://groups.google.com/forum/#!msg/bigquery-announce/l0kwVNpQX5A/ct0MglMmYMwJ
If you make API calls that are authenticated as an end user, then API calls will soon return errors when the end user has not accepted the updated Terms of Service. Apps built against the BigQuery API should ideally look for those errors and direct the user to the Google APIs Console to accept the new terms.
Except I dont really understand how to do this.
Also all the potential user accounts that I have tested my app with have access to a specific project that has Big Query API enabled, and can use the API so why does this pop up?
Also there are times when a specific account does not run into this problem. For instance if I keep refreshing and retrying to use the app eventually it will not have this problem and work. But then the next time this error will resurface again.
I don't understand how a user can have accepted the terms of service at one point of time and then not another at some point in the future?

Answer 1

Yes, any end users who authorize access to the BigQuery API must accept the Terms of Service (ToS) provided by the Google Developers Console at https://developers.google.com/console
It is possible that Terms of Service can change, and that some of your project members have not yet accepted updated BigQuery ToS. If one of your users is receiving this message when authorizing access to the BigQuery API, you redirect them to the https://developers.google.com/console to accept the terms of service.
Re: "specific account does not run into this problem" - can you confirm this is happening consistently with a specific account on a specific project?