@JohnF    Many reasons why meter sendings fail, most likely intermittent mobile signal.   Meanwhile get online and look for help for reading the type of meter you have, your installer should have told you how to read it but often they do not bother. You should be able to guess the correct menu item by seeing a reading that is in sequence to the previous automatic readings.  
It is ironic that if the auto system fails then smart meters are much harder to read correctly than traditional meters. Is this a good design feature? no it is  lazy metering design done with no allowance for consumer skills. So many different meter brands are used, why on earth did the authorities not make them all similar with an intuitive system, like a big button that is labelled Readings. Huh.