Excel VBA setting named cell formula using range property - vba

Question

hoping you can help. Banging my head against the wall at this point. Fairly new to writing VBA. I have some VBA code listed below. Essentially, what I am trying to do is lock/unlock, change fill color, and set formula for a range of cells based on the input from a drop down menu using the worksheet change event and ActiveSheet. The code lives on the sheet itself. Everything works fine except for the formula setting piece.
Private Sub Worksheet_Change(ByVal Target As Range)
With ActiveSheet
.Unprotect Password:="somepw"
If Range("d17").Value = "Yes" Then
.Range("D22:D78").Locked = False
.Range("D22:D78").Interior.Color = RGB(115, 246, 42)
.Range("Inc_06PCTotRev").Formula = "=SUM($D$22:$D$25)"
ElseIf WorksheetFunction.CountA(Range("d22:D78")) <> 0 Then
If .Range("D22").Locked = True Then
With Range("D22:D78")
.Locked = False
.ClearContents
.Interior.Color = RGB(217, 217, 217)
End With
Else: .Range("D22:D78").ClearContents
End If
Else: .Range("D22:D78").Interior.Color = RGB(217, 217, 217)
.Range("D22:D78").Locked = True
End If
.Protect Password:="somepw"
End With
End Sub
When that is included I receive an error stating "method range of object _worksheet failed" and excel crashes. If I comment it out it fires without issue. Any help would be greatly appreciated. Please let me know if this isn't specific enough or doesn't make sense and I'll try my best to expand.

Answer 1

As I posted in my comments you are in a never ending loop because you change your worksheet in the worksheet change event. You need to keep track of the change call. Can alleviate this by creating a variable to keep track of when you called the change, this also is assuming that the name range is 1 cell.
Public bRunning As Boolean 'keeps track of when we are making the change
Private Sub Worksheet_Activate()
bRunning = False 'set to false when the sheet is activated
End Sub
Private Sub Worksheet_Change(ByVal Target As Range)
If bRunning = False Then 'check to see if this is the first change
bRunning = True 'set the variable letting us know we are making the change.
With ActiveSheet
.Unprotect Password:="somepw"
If Range("d17").Value = "Yes" Then
.Range("D22:D78").Locked = False
.Range("D22:D78").Interior.Color = RGB(115, 246, 42)
.Range("Inc_06PCTotRev").Formula = "=SUM($D$22:$D$25)"
ElseIf WorksheetFunction.CountA(Range("d22:D78")) <> 0 Then
If .Range("D22").Locked = True Then
With Range("D22:D78")
.Locked = False
.ClearContents
.Interior.Color = RGB(217, 217, 217)
End With
Else: .Range("D22:D78").ClearContents
End If
Else: .Range("D22:D78").Interior.Color = RGB(217, 217, 217)
.Range("D22:D78").Locked = True
End If
.Protect Password:="somepw"
End With
Else
bRunning = False 'reset the variable as we are done making changes
End If
End Sub

Answer 2

If you only need to perform a SUM when your routine is called, you can use the Worksheet.Sum function:
Application.WorksheetFunction.Sum(Range("$D$22:$D$25"))
If you actually need a formula in that cell, consider using the FormulaR1C1 function:
.Range("Inc_06PCTotRev").FormulaR1C1 = "=SUM(...)"
Lookup FormulaR1C1 in under Excel help to gain a better understanding of the R1C1 referencing syntax. If the cell you want to insert the formula in is $D$26, you would replace the "..." above with "R[-4]C:R[-1]C". If the formula is supposed to be in cell $E$20, you would replace the "..." above with "R[2]C[-1]:R[5]C[-1]".
R[#] references the # of rows from the destination range/cell and C[#] referenced the # columns from the destination range/cell.