The ringtone of SMS can't be changed.

Please recall that before this problem occurred, did you install software or accept other files, and did your mobile phone get root permission? If so, please temporarily delete these softwares and turn off root privileges. See if it's normal. Still no good, you can try the following solution step by step: 1. It is recommended that you upgrade to the latest development version with a wire brush, and don't get root permission and install system security software for the time being. Try to solve it. You can refer to the following brushing tutorial:

A. First, you download a newly developed line brush package from Xiaomi official website. This is the link:/topic-mirom.html.

B. During downloading, please back up data, enter recovery (shutdown, press and hold the volume increase+power on key to enter recovery), and clear the cache, user data and all data. Install the driver on the computer and download a miflash brush tool. This is the driver installation link:/thread-504332-1-1.html/thread-3104435-65438+.

D. If you are not familiar with brushing, please refer to the brushing video tutorial made of rice flour: /forum.php? View thread & amptid=2742326

A more detailed description of the problem will help netizens understand your troubles and help you solve the problem more accurately. Thank you for supporting Xiaomi mobile phone!