This is the original VISA Open function. It required a VISA Reference constant and a string input for the resource name (i.e. GPIB0::INSTR::5). Older instrument drivers were written with this and when updated to newer versions of LabVIEW, are marked as VISA Old. You should replace the VISA Old with the current VISA Open. Delete the string control, make the VISA Reference visible, and connect the VISA Reference to the connector pane where the string was. This should be the upper left most connector.