Using Edit doctype what is allowed?

[aakvatech]

How to change doctype setting

Good morning all, I have installed Bench, Frappe, Erpnext with --setup-production. I’d like to change some settings in the doctype “Purchase Receipt”. I would like the field “Remarks” of that doctype to be printable. I am not able to un-click the field “Print Hide”. Actually I am not able to change anything in that doctype. I am logged in as administrator. Any idea on how I can tune settings of doctype? Thanks François