"Message not sent, check message and try again" appears on Samsung mobile phone. I don't know why?

Dear Samsung users:

Based on your description, it is recommended that you do the following:

1. Check whether the mobile phone bill is sufficient.

2. Check whether the information center number is entered correctly: Information - Menu key - Settings - SMS settings - Information center - Set information center number (please contact the local network operator for the information center number).

3. Check the phone for virus software. Check method: Settings-Application Manager-Running-Check whether the Com.android.version process is running. If this program exists, please uninstall it and restart your phone.

4. Try changing other SIM cards.

5. Check whether the machine has firmware/system update push notifications. If so, please upgrade the phone to the latest version.

6. If it doesn’t work, please back up the data in your phone (contacts, multimedia files, etc.) and restore the machine to factory settings. (Note: Back up relevant data before updating the version or restoring to factory settings to avoid affecting use)

For comments, suggestions, and complaints, please click: support.samsung.com.cn/survey