Hi,
This error indicates that there's something wrong with your connection or the SIM card plan, more detailed causes:
- The phone number you try to send your message to is invalid
- There is no network coverage
- You don't have enough money on a prepaid subscription
- The short message service center of the GSM network operator is temporarily out of service
- The GSM cell is overloaded
Please check if you have the antenna connected and card works normally with other devices (can send SMS messages and so on).
EB.