我使用环聊与朋友聊天。当我不想保留历史时，我将它设置为关闭。 因此，每当我聊天时，在输入线中，我会看到"历史记录关闭" 的常量消息。但是，当我再次打开Hoogouts时，我可以看到日期前发送的消息。
I use Hangouts to chat with friends. As I don't want to keep history, I set it to be turned off. So whenever I chat, in the input line I see a constant message of "History is turned off".
However, when I open Hangouts again, I can see messages that were sent days ago.
A simple question: how can I see older messages with history disabled?
The history setting only affects messages as they are sent. Turning history off doesn't delete old messages that were sent while history was turned on. If you want to delete your old messages as well as stopping new messages being saved, you can do this with Delete in the chat's menu (or Delete history in the web-based client).
Go to settings, apps and touch the app, and click clear data. Now check if you are able to change the settings and the the settings works.