Google Play 订单校验错误：The project id used to call the Google Play Developer API has not been linked in the Google Play Developer Console

问题背景

在调试Google Play订单校验功能时，遇到一个非常奇怪的错误：

The project id used to call the Google Play Developer API has not been linked in the Google Play Developer Console

首先，确认在Google Play Developer Console中正确配置Service Account，并且已经关联相应的project到Google Play Console。

其次，确认代码中用到的账号email和key是正确的。

最后，试一下打一个新包提交到Google Play Console上……