A known error has been created after diagnosis of a problem was complete but before a workaround has been found. Is this a valid approach?

ITIL states that a known error record can be raised at any stage of the problem management lifecycle whenever it is useful to do so. The purpose of the record is to document that a root cause has been identified so that the information can be shared across support teams and duplicate diagnostic work is avoided. A workaround does not need to be in place first - capturing the diagnostic findings early has value even while a fix or workaround is still being developed.

ITIL defines a known error as resulting from problem diagnosis, which logically follows the problem record; a known error cannot be created before the problem is even logged.

A known error record requires prior investigation to identify a root cause and is not created at the time an incident is raised, which is too early in the process for a diagnosis to exist.

Known error records are independent of release schedules and should be created as soon as the diagnostic information warrants it, not deferred until the next service release.