I suddenly can't send or receive texts from a family member and keep getting Error 31: Other network problem. I have a s9+ and the person i am trying to text has an iphone. We are on the same plan in same household and it is another family member. We have never had problems texting before. This problem just started occuring. I can still text anyone else in my contact list no mater what type of phone they have. i have totally deleted her from my contacts then removed and reinstalled my sim card and then tried to text her directly from my keypad. It still is giving me the Error 31 message. Can anyone help me figure out why this is still hapening? Any suggestions?