Every time I run my workflow in Docubee it is cancelled immediately with no error message. Why?

I run the workflow (programmatically or manually) and the workflow process immediately shows cancelled. This produces no error message. Why is this happening?

Most likely the Expiration timer is set to 0,0,0. Meaning 0 minutes, 0 days and 0 years. This is the default when you click to move the Enable Workflow Expiration slider which was most likely done by accident.