Wechat can't send and receive messages between 2 am and 4 am.

Wechat suddenly can't send a message for the following reasons:

1. The mobile phone network is unstable. We can check the mobile phone network by opening the webpage.

2. There is too much information in WeChat memory. You can click "Settings", select the "General" menu, and then click "Clean up WeChat storage space".

3. There are too many WeChat chat records, and some chats can be made clear.

4. If you are blacked out by the other party, you can send a message to others to see if it is successful, so as to know whether it is blacked out by the other party.