A user starts a workflow in Vault. A task assigned to the user is not received.
Check the audit trail to verify if the user is replaced as a participant.
Review the audit history of the document to verify if a task is assigned to the user. The audit trail shows any system change where a new user is added to the role at the time the task is assigned. If the user is replaced on a current task, the audit trail shows the replacement being performed by the user at the time the change is made.