Connectivity error have different causes, as specified below:
The SIM you're using is not recognized because the modem is network locked. You will have to unlock the modem to accept SIM cards from different carriers.
The service is limited since you are in an area with low or missing signal.
You don't have enough credit left or the service is suspended.
The modem is not configured properly with a number to call to connect to the Internet.
For all these probable causes, contact the carrier of the SIM card to see if there is something wrong.
