Message 'Fiscal periods of the requested period type for the plan duration do not exist' is seen when viewing the timeline of a Roadmap:
Our fiscal periods cover the duration of the Roadmap.
Release : SAAS
Component : Clarity Roadmaps
To stop the message from occurring, go to the Grid View of the Roadmap and select 'View Options'. Then set:
Start Period: Roadmap Start
End Period: Roadmap Finish
After setting these, The message no longer occurs.