Trailhead chhalendge:
Create a flow to streamline entry of new accounts, contacts, and opportunities.

error: 
UPSERT --- UPSERT FAILED --- ERRORS : (REQUIRED_FIELD_MISSING) Required fields are missing: [StageName] --- for SFDC record with ID : null,
 

Trying to save a flow page labeled FlowPage
New Customer Flow is not found or does not have a active version

<apex:page >
  <flow:interview name="New Customer Flow"/>
  </apex:page>
Flow "New Customer Flow" had been created and it does show as being active