SMS has been working normally, and suddenly it can't be used. What is the reason?

When the short message function of mobile phone can't be used normally, you can check it according to the following steps: Step 1: Please turn off the UIM card and then turn it on to test whether it is normal, and check whether the mobile phone has downloaded some system software, which will affect the sending and receiving of short messages. If yes, please uninstall it in time; Step 2: Please replace the mobile phone and test it to determine whether there is any problem with the mobile phone terminal or settings. Step 3: Check whether the number is set as SMS blacklist or spam number by yourself or the other party's mobile phone. If so, please cancel the setting. Step 4: If you can't check the settings, please back up the important files and address book on your mobile phone, restore the factory settings or initialize; Step 5: After the above operations, it is still not restored or does not have the conditions for reloading test. Please go to the nearest telecom business hall for replacement test or consultation. Click "official website" Customer Service 22 1 below for more service offers.