nobody verified
No body
The body could not be fetched from the message store, or personalisation failed.
In detail
Two unrelated causes share one counter: an external message store that did not answer, and a template that could not be rendered. Both produce a message with nothing to send. For a node using the store, this is the counter that says the store is the problem. For a node without one, any non-zero value is a personalisation bug in our own content.