Text messaging - cant send text messages

I just got 2 text messages and when i go to read them, it keeps telling me that there is a download failure, connection error, please try again later. what can i do, please help. I cant send text messages. Keeps saying 'sending failed'. Not even sure if i can stil receive them. I am still able to make calls.

If you have nokia symbion phone so formate it and any brand you have for that you need to check sim center number or reset the phone