Outbox at Workflow Disappear

[Sanusi Oetomo]

Hi workflower,
 
I've a strange experienced about Outbox at client Workplace. There are some
missing data.
Yesterday they executed some work item and It looked ok. But today when we
check in the outbox, the Workflow item is not there.
My question: How can this happened ? How to show the missing data again so
we can continue normally?
 
Any suggestion will be appreciated.
 
Best regards
Sanusi
PTME.