Dennis @ PerfectForms
A stage cannot be both default and closed. Your workflow needs at least two stages. The first should be the default stage and the second, a closed stage. There should be a condition to move from one to the other. That way the instance will only move to the closed stage when the condition has been met. That condition can be anything (like a checkbox is checked).
Please watch our free training video about workflow: /tutorialvideos/workflow/workflow.htm.