Another reason can be that your SIM card is locked by a PIN. To unlock it, you must connect to the Web UI and enter the PIN code. Please follow the procedure described in the following section: How do I enter my SIM PIN code?
Finally, it is also possible that your SIM card is detected but not automatically recognized by the device. In this case you must connect to the Web UI and check the APN settings of your service provider. This procedure is explained in the following section: How do I check and edit the APN settings of my service provider?
