Description: Occasionally you misclick on something in the actions drop down and your fields disappear. Here is how to get it back.
Software Version: All
1. In the Document View screen - go to the Action Menu.
2. Go down to "Show Fields". This brings the Workflow/History/etc fields back.
Another reason is that the content type assigned to that Document may not have a Workflow assigned to it.
Follow the instructions on how to Edit/Create a new content type.