If you get this error message, try editing the APN data under Settings->General->Network->Cellular Network (in spanish: Ajustes->General->Red->Red de datos móviles ) Alternative 1: APN: internet.gprs.unifon.com.ar Username: internet Password: internet Alternative 2: APN: wap.gprs.unifon.com.ar Username: wap Password: wap CLARO APN's Alternative 1: APN: igprs.claro.com.ar Username: clarogprs Password: clarogprs999 Alternative 2 (old but still works): APN: internet.ctimovil.com.ar Username: ctigprs Password: ctigprs Alternative 3: APN: wap.ctimovil.com.ar Username: ctigprs Contraseña: ctigprs999 from source 1 and source 2