Error Performing Actions on Only Formula Cells - excel

Question

I was attempting to loop through every worksheet in every workbook in a folder and make sure only the cells containing formulas were locked. I have already been using code to lock all cells in every worksheet, and code to lock every formula in a worksheet, successfully for a few months, so I basically mashed the two pieces of code together to get this:
Sub LockAllFormulas()
Dim myOldPassword As String
Dim myNewPassword As String
Dim ws As Worksheet
Dim FileName As String
Dim rng As Range
myOldPassword = InputBox(Prompt:="Please enter the previously used password.", Title:="Old password input")
myNewPassword = InputBox(Prompt:="Please enter the new password, if any.", Title:="New password input")
FileName = Dir(CurDir() & "\" & "*.xls")
Do While FileName <> ""
Application.DisplayAlerts = False
If FileName <> "ProtectionMacro.xlsm" Then
MsgBox FileName
Workbooks.Open (CurDir & "\" & FileName)
For Each ws In ActiveWorkbook.Worksheets
If Not Cells.SpecialCells(xlCellTypeFormulas) Is Nothing Then
ActiveWorkbook.ActiveSheet.Unprotect Password:=myOldPassword
ActiveWorkbook.ActiveSheet.Cells.Locked = False
For Each rng In ws.Cells.SpecialCells(xlCellTypeFormulas)
rng.Locked = True
Next rng
ActiveWorkbook.ActiveSheet.Protect Password:=myPassword
End If
Next ws
ActiveWorkbook.Save
ActiveWorkbook.Close
End If
FileName = Dir()
Loop
Application.DisplayAlerts = True
End Sub
Every time I run it it shows a 400 error. The error matches one I got whenever the code runs into a sheet that doesn't have any code in it, but I thought I fixed that problem when I added:
If Not Cells.SpecialCells(xlCellTypeFormulas) Is Nothing Then
Any ideas what else could be going wrong?

Answer 1

When working with SpecialCells, you have to be very careful. What I do is I store them in a range sandwiched between OERN and then check of they are not nothing. Here is an example
Dim rng As Range
On Error Resume Next
Set rng = ws.Cells.SpecialCells(xlCellTypeFormulas)
On Error GoTo 0
If Not rng Is Nothing Then
'
'~~> Rest of the code
'
End If
Applying that to your code will be like this (UNTESTED)
Dim LockedRange As Range
For Each ws In ActiveWorkbook.Worksheets
With ws
On Error Resume Next
Set LockedRange = .Cells.SpecialCells(xlCellTypeFormulas)
On Error GoTo 0
If Not LockedRange Is Nothing Then
.Unprotect Password:=myOldPassword
.Cells.Locked = False
LockedRange.Locked = True
.Protect Password:=myPassword
End If
Set LockedRange = Nothing
End With
Next ws