#NAME? error in Excel for VBA Function

Question

I am making my first VBA program and trying to run the following function. The function checks a specific named range for the first row which does not have a value greater t

Answer 1

When Excel opens an unkown workbook containing VBA-Code, it usually asks for macros to be enabled by the user (depending on the application settings).

If the user then enables the macros, all event-driven procedures will be started, such as auto_open or others.

Custom VBA Functions however require for a full recalculation of the workbook. Otherwise the functions return-value still is #NAME, as the calculation is only done directly after opening the workbook.

In order to work directly at the first time opening, one has to add the following line to the workbook_open event

'
' Workbook open event
Private Sub Workbook_Open()
    Application.CalculateFullRebuild
End Sub