I have a custom Excel function that is supposed to take a range and count the number of values, where some cells may contain multiple /-delimited values, each of which must be counted. Here's the function:
Option Explicit
Public Function COUNT_RACKS(rack_range As Range) As Integer
    Dim total As Integer
    Dim cell As Range
    Dim split_str As Variant
    Dim len_str As Integer
    total = 0
    For Each cell In rack_range.Cells
        If Len(cell.Value) > 0 Then
            If InStr(cell.Value, "/") <> 0 Then
                split_str = Split(cell.Value, "/")
                len_str = Len(split_str)
                total = total + len_str
            Else
                total = total + 1
            End If
        End If
    Next cell
    COUNT_RACKS = total
End Function
The trouble is, it's throwing #VALUE! errors. In stepping through the function in the debugger, it seems like there's a problem with the line len_str = Len(split_str). I say this because whenever I get to this line in the debugger, it immediately stops debugging and does, essentially, an F5. Obviously there's one or more bugs in my code, but without my debugger being willing to show me the errors, how can I debug it?
What's wrong with the code?
