JnextPlan fails with message AWSJPL017E

You receive the following message from JnextPlan: 
AWSJPL017E The production plan cannot be created because a 
previous action on the production plan did not complete successfully. 
See the message help for more details.

Cause and solution:

The problem might be caused by a JnextPlan being launched before the previous JnextPlan has run the SwitchPlan command.

The situation might not resolve itself. To resolve it yourself, perform the following steps:
  1. Reset the plan by issuing the command ResetPlan -scratch
  2. If the reset of the plan shows that the database is locked, run a planman unlock command.