VBA/Excel suddenly running slow with no code changes

Question

I came to work this morning and began work on the same file I left from yesterday. Now Excel slows way down whenever a macro is assigning values to cells or clearing them. It was lightning quick before I left yesterday, now it takes 2-3 seconds at a time to assign a value to a cell.

Right now, other files with similar macros run fine. This happened to another file a while back, so I reverted to a previous version of the file and it worked fine, while the slow file continued to work slow. I guess I can do that now, but in this case that would take a whole lot of work to bring that file to where I have this version. I was wondering if anyone knows what might be going on. Is this one of the things Excel files just do from time to time (like a kind of file corruption), or is there a fix?

I have provided the macro below, although it happens throughout the file whenever values are assigned to cells. I've marked the trouble areas by denoting <---SLOW HERE .

I know this all sounds very vague, and I know I am giving very little to go on. Perhaps insufficient info, but this is all I have. There is no reason (that I can see) that this should be happening. I've even restarted the computer...just in case the problem was external to Excel. No change.

If you need more info I will do my best to expound if I can. Thanks for your help and understanding.

Example Macro:

Sub DeleteButton1_Click()
   Call UnlockSettingsWorksheet

   Sheet24.Range("C18:E18").Value = ""  <---SLOW HERE 
   Dim i As Long
   For i = 18 To 21
     Sheet24.Range("C" & i & ":E" & i).Value = Sheet24.Range("C" & i + 1 & ":E" & i + 1).Value  <---SLOW HERE  
   Next
   Sheet24.Range("C22:E22").Value = ""  <---SLOW HERE 

   Call LockSettingsWorksheet
End Sub

Answer 1

As mentioned in the comments, there might be a lot of factors contributing to this change:

• any actions triggered in these events:

  • Worksheet_Calculate()
  • Worksheet_Change()
  • Worksheet_FollowHyperlink()
  • Worksheet_SelectionChange()
  • Workbook_SheetCalculate()
  • Workbook_SheetChange()
  • Workbook_SheetFollowHyperlink()

• external links, and the external file(s) moved or deleted

• database connections (check Data Tab -> Connections) (doubtful)
• Invalid Named Ranges (Formula Tab -> Name Manager; any Refs?)
• Data validation rules (Data Tab -> Data Validation -> clear all)
• Are you opening the file from a network location - this will make it much slower
• Conditional Formatting rules? - remove all
• Any hidden objects? ( Alt + F10 - delete all)
• Hidden formatting (what is the last used cell with data?); this may not be relevant for your case
• Corrupt file

If the file is corrupt, and it's feasible, try re-creating it from scratch, and run this function first

If it's not corrupt, one of the first things I'd try is to disable all Excel functionality before the macro:

---

Sub DeleteButton1_Click()

    'UnlockSettingsWorksheet

    FastWB          '<--- Disables all Application and Worksheet level settings

    With ThisWorkbook.Worksheets("Sheet24")   'Fully qualified worksheet

        .Range("C18:E18").Value2 = vbNullString

        Dim i As Long
        For i = 18 To 21
            .Range("C" & i & ":E" & i).Value2 = .Range("C" & (i + 1) & ":E" & (i + 1) ).Value2
        Next

        .Range("C22:E22").Value2 = vbNullString

    End With

    XlResetSettings '<--- Restores all Excel settings to defaults

    'LockSettingsWorksheet

End Sub

---

.

---

Public Sub FastWB(Optional ByVal opt As Boolean = True)
    With Application
        .Calculation = IIf(opt, xlCalculationManual, xlCalculationAutomatic)
        .DisplayAlerts = Not opt
        .DisplayStatusBar = Not opt
        .EnableAnimations = Not opt
        .EnableEvents = Not opt
        .ScreenUpdating = Not opt
    End With
    FastWS , opt
End Sub

Public Sub FastWS(Optional ByVal ws As Worksheet, Optional ByVal opt As Boolean = True)
    If ws Is Nothing Then
        For Each ws In Application.ThisWorkbook.Sheets
            OptimiseWS ws, opt
        Next
    Else
        OptimiseWS ws, opt
    End If
End Sub

Public Sub OptimiseWS(ByVal ws As Worksheet, ByVal opt As Boolean)
    With ws
        .DisplayPageBreaks = False
        .EnableCalculation = Not opt
        .EnableFormatConditionsCalculation = Not opt
        .EnablePivotTable = Not opt
    End With
End Sub

---

Public Sub XlResetSettings()    'default Excel settings
    With Application
        .Calculation = xlCalculationAutomatic
        .DisplayAlerts = True
        .DisplayStatusBar = True
        .EnableAnimations = False
        .EnableEvents = True
        .ScreenUpdating = True
        Dim ws As Worksheet
        For Each ws In Application.ThisWorkbook.Sheets
            With ws
                .DisplayPageBreaks = False
                .EnableCalculation = True
                .EnableFormatConditionsCalculation = True
                .EnablePivotTable = True
            End With
        Next
    End With
End Sub

---

Maybe this will eliminate some VBA causes

Answer 2

I started noticing Range.Value = ... operations being significantly slow once upgraded to a 64 bit edition. Aside form the normal stuff like .ScreenUpdating and .Calculation , two things I've discovered significantly improve the speed are:

1. Change the cursor to xlWait prior to your operation, and back to xlDefault once done.

    Public Sub MyMacro() On Error Goto Exception Application.Cursor = xlWait ' Do something here. Exception: Application.Cursor = xlDefault End Sub 

2. Use .Value2 instead of .Value

    Sheet1.Range("A1").Value2 = "The quick brown fox jumps over the lazy dog."