Google identity toolkit returns “Backend error”

问题

Our application using google-identity-toolkit for authentication is receiving a 500 "backendError" from the verifyAssertion API. This occurs about 30% of the time and started happening about 1 week ago. 70% of the time the call succeeds. Our app has not changed in 6 months. Is there a broken server out there in the pool somewhere?

Error message:

{
 "error": {
  "errors": [
   {
    "domain": "global",
    "reason": "backendError",
    "message": "Backend Error"
   }
  ],
  "code": 500,
  "message": "Backend Error"
 }
}

来源：https://stackoverflow.com/questions/32193089/google-identity-toolkit-returns-backend-error