If Field from Window is marked as "Quick Entry", but not with "Displayed", you will get an empty line on its place in Quick Entry form.
I don't think that they should be processed in the org.adempiere.webui.grid.WQuickEntry.initPOs() method.
In quick entry the display logic show/hide the field in the empty space provided - the change here is not trivial as it would require repainting the fields on every field change.
Anyways the impact is really minor, just a presentation issue.
triaged by Andres Lopez
Open Invoice (Vendor)
On new record, right clic on Business Partner and select New
Change rol to System and set greeting field Displayed = N
change rol to GW Admin and test it
Same error reported