Service Request Folders: How to hide mandatory fields in the Service Request header section

Hi,

I need to hide mandatory fields from the SR top section and only display them in the Workbench tab.  

But when I try to hide via folders the error message :You cannot hide this field

The fields in question are:  'Problem Summary', 'Note Type', 'Note Description' and 'Note Visibility'

These fields were hidden in our 12.1.1 instance but cannot do the same in 12.1.3

Thank you,

Ingrid