对我来说，是日期的问题。更新后问题已解决。

允许读/写:

 if request.time < timestamp.date(2020, 5, 21);

编辑:如果您仍然感到困惑，无法找出问题所在，请查看firebase控制台的规则部分。

以上投票的答案对数据库的健康是危险的。你仍然可以让你的数据库只用于读取而不用于写入:

  service cloud.firestore {
    match /databases/{database}/documents {
     match /{document=**} {
       allow read: if true;
       allow write: if false;
      }
   }
}

确保你的数据库不是空的，你的查询是不存在的集合

时间限制可能已过

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {

    // This rule allows anyone on the internet to view, edit, and delete
    // all data in your Firestore database. It is useful for getting
    // started, but it is configured to expire after 30 days because it
    // leaves your app open to attackers. At that time, all client
    // requests to your Firestore database will be denied.
    //
    // Make sure to write security rules for your app before that time, or else
    // your app will lose access to your Firestore database
    match /{document=**} {
      allow read, write: if request.time < timestamp.date(2020,7, 1);
    }
  }
}

这一行更改了日期:

 allow read, write: if request.time < timestamp.date(2020,7, 1);

https://console.firebase.google.com

开发->数据库->规则->设置读、写-> true

进入数据库->规则:

然后更改如下规则

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if false;
    }
  }
}

以下

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if request.auth != null;
    }
  }
}