_screen.AddProperty("PrintScr") && add the property (no error) >? PEMSTATUS(_Screen,'Printscr',4) && returns .T. >? PEMSTATUS(_Screen,'xPrintscr',4) && gives error re invalid argumentInterestingly the command following run immediately after returns .F.
? PEMSTATUS(_Screen,'xPrintscr',5)While it may be (don't know) that a property added by AddProperty is not considered to be "user defined", I don't think that using "4" should generate an error.