What can cause Range.Copy error?

I have the following line in VBA code:

wks.Rows(lLastRow).Copy

      

        
        
        
      

    

It usually works fine. lLastRow is always 11. wks is always the active sheet.

But sometimes the line above starts throwing errors like "range class copy method failed".

Then I need to reload the Excel file for the line to start working again.

Do you have any idea what might be causing the problem? What can cause the operator to Range.Copy

stop working and then start working again after restarting the file?

EDIT : Here is my code. The code is triggered by a button callingNewActionButton()

Sub NewActionButton()
    'Dim runState As New cRunState
    'Set runState = New cRunState
    If bProduction = True Then On Error GoTo ErrHandler

    'START
    Dim lStart As Long
    Dim lId As Long
    Dim lDate As Long
    Dim lEnd As Long
    Dim wks As Worksheet

    Set wks = GetSheetByCodename(ThisWorkbook, "wActions")
    lStart = 2
    lId = 3
    lDate = 2
    lEnd = 12

    Call NewRow(wks, lStart, lId, lDate, lEnd)
    'END

    On Error GoTo 0
Exit Sub
ErrHandler:
    MsgBox ("Ett of" & oe & "rutsett fel har skett.")
End Sub

      

        
        
        
      

    

The procedure in which I am getting the error. the first time it fails, it seems to throw an error in the .Insert statement. Then if I run the macro again it throws an error in the .Copy expression. If I restart the document it works.

Sub NewRow(wks As Worksheet, lStartCol As Long, lIdCol As Long, lDate As Long, lEndCol As Long)
    Dim lLastRow As Long
    Dim rConstants As Range
    Dim rConstant As Range
    Dim rEarlierIds As Range

    'Determine last row based on criteria column
    lLastRow = LastRow(wks.Columns(lIdCol))

    'Copy template row from directly above
    wks.Range(wks.Cells(lLastRow, lStartCol), wks.Cells(lLastRow, lEndCol)).Copy

    'Insert new row
    wks.Range(wks.Cells(lLastRow + 1, lStartCol), wks.Cells(lLastRow + 1, lEndCol)).Insert

    'Remove unwanted properties
    Set rConstants = wks.Range(wks.Cells(lLastRow + 1, lStartCol), wks.Cells(lLastRow + 1, lEndCol)).SpecialCells(xlCellTypeConstants)
    If Not rConstants Is Nothing Then
        For Each rConstant In rConstants.Cells
            rConstant = ""
        Next rConstant
    End If

    'Add ID
    Set rEarlierIds = wks.Columns(lIdCol)
    wks.Cells(lLastRow + 1, lIdCol) = Evaluate("Max(" & rEarlierIds.Address & ")+1")

    'Add Date
    wks.Cells(lLastRow + 1, lDate) = Date

    'Remove copy marking
    Application.CutCopyMode = False
End Sub

      

        
        
        
      

    

EDIT2 : The .Insert statement inserts a new range. However, in spite of this, execution stops and I get the error "Insert method of the Range class could not be inserted. So the line does the job, but I get an error and the execution stops."

EDIT3 : I don't know what is wrong, but I found a pattern. The .Insert statement works if I run the macro immediately after opening the Excel file. And I can do it as many times as I want. But as soon as I double click on a cell and then press ESC to leave the cell and then try running the macro again, then the .Insert statement throws an error. It doesn't make sense to me.

EDIT4 . I have updated the code above as it currently looks like.

EDIT5 : The code below works flawlessly. What I changed is that I do not copy and paste. Instead, I first insert a new line and then copy it. I still don't know why my previous code didn't work. I hope someone has an idea or can confirm that I have stumbled upon an error and can say something about what circumstances are causing the error.

Sub NewRow(wks As Worksheet, lStartCol As Long, lIdCol As Long, lDate As Long, lEndCol As Long)
    Dim lLastRow As Long
    Dim rConstants As Range
    Dim rConstant As Range
    Dim rEarlierIds As Range

    'Determine last row based on criteria column
    lLastRow = LastRow(wks.Columns(lIdCol))

    'Insert new row
    wks.Range(wks.Cells(lLastRow + 1, lStartCol), wks.Cells(lLastRow + 1, lEndCol)).Insert

    'Copy template row from directly above
    wks.Range(wks.Cells(lLastRow, lStartCol), wks.Cells(lLastRow, lEndCol)).Copy

    'Paste formulas row
    wks.Range(wks.Cells(lLastRow + 1, lStartCol), wks.Cells(lLastRow + 1, lEndCol)).PasteSpecial xlPasteFormulas

    'Remove values
    Set rConstants = wks.Range(wks.Cells(lLastRow + 1, lStartCol), wks.Cells(lLastRow + 1, lEndCol)).SpecialCells(xlCellTypeConstants)
    If Not rConstants Is Nothing Then
        For Each rConstant In rConstants.Cells
            rConstant = ""
        Next rConstant
    End If

    'Add ID
    Set rEarlierIds = wks.Columns(lIdCol)
    wks.Cells(lLastRow + 1, lIdCol) = Evaluate("Max(" & rEarlierIds.Address & ")+1")

    'Add Date
    wks.Cells(lLastRow + 1, lDate) = Date

    'Remove copy marking
    Application.CutCopyMode = False
End Sub