I have a Journey which sends the Subscriber SMS messages, 2/4 journey entries (all unique subscribers) don't receive the SMS.
The error displayed in the SMS activity in my Journey History is the following:
Failed - Object reference not set to an instance of an object.
Can anyone advise what this means? If it was configuration surely all subscribers wouldn't receive the message? I can confirm all subscribers have a mobile number and they use the same format and country code. Not sure if it helps but the entry source is Salesforce Data Entry.
There can be entries where the Subscriber record does not exist in the AllSubscribers list as they do not have email addresses attached (only mobile numbers) but my journey only contains SMS message activities, no email. I have checked and even on some Subscribers that do have AllSubscribers records suffer the same activity error.