Error when exporting unmanaged solution: Business Process Error, Invalid Business Process

Tonight when trying to export a solution, I received the following error:┬áBusiness Process Error, Invalid Business Process. The blue link “Show technical details” did nothing.

The reason was that I had use dthe “Save as” button on a business process to create a backup. That backup was never activated, it always stayed in draft mode. Simply removing that process from the solution allowed me to export that solution successfully!