Which status is a problem, assigned when its cause has been recognized?

An Incident is an unplanned interruption or degradation of an IT service and focuses on restoring service quickly, not on identifying or documenting root cause.

A Request for Change (RFC) is a formal proposal to modify a service, configuration, or infrastructure component - it is a change management record, not a problem status.

A Known Error is a formal ITIL problem management record status indicating that the root cause of a problem has been successfully diagnosed. It is distinct from an unresolved problem in that the underlying cause is now understood, and a workaround or permanent fix pathway is typically documented alongside it. This status allows teams to track the issue and communicate its known state until a permanent resolution is deployed.

A Workaround is a temporary measure used to reduce the impact of a problem or incident; it is a technique or action, not a status classification in ITIL problem management.