When I am trying to edit a document set, the Edit Properties form only shows the Name field and no other properites from the document set. View Properties shows all the properties of the document set just fine, I've checked and the columns are set to Optional, so these should show up in the Edit Properties form. When I create a document set, all the properties show up. There have been no customizations to the default edit form. What am I missing, why are the properties of the document set not showing up on the Edit Properties form?
As a service to anyone who has ever experienced this bizarre problem, here is an obscure solution that worked for me:
Depending on the circumstances it may be relevant, particularly if you've ever edited the form page.
Edited on request: ----%<---- When you add a list web part to a document library display or edit form, it adds a line of code to the dispform.aspx or editform.aspx.
After commenting out the line (on both the dispform and the editform), everything was back to normal and the users could see and edit all of the properties.
This seems to occur only on document library forms as my list forms with added web parts were not effected. ----%<----
In my case, I had added a list view web part showing the document set contents to a form in another list. Sure enough, the line was added to the two forms and removing it solved the problem.