Excel runtime error trying to add new rows to a table

Excel novice here again - old dog new tricks. I've been working on some data entry userforms in my workbook, and an encountering a runtime error whenever I try to add new blank rows to an existing named table. The runtime error code is -2147417848 (80010108) "Method 'Add' of object 'ListRows' failed. The table is not protected, the cells are not protected, the table only has 16 existing rows. I've tried reconstructing the code from scratch and splitting the code up to separate subroutines to first add the empty rows, then add data to the rows. Can anyone decipher why this happens? I really need to solve this so I can complete the rest of my work. Here's the code:

Private Sub cmdSaveTB_Click()
    Dim ws As Worksheet
    Dim tbl As ListObject
    Dim lastRow As Long
    Dim i As Long
    Dim username As String
    Dim currentDate As Date
    Dim valuesArray As Variant
    
    ' Set references to the worksheet and table
    Set ws = ThisWorkbook.Sheets("TB_Database")
    Set tbl = ws.ListObjects("tbl_TBTabulation")
    
    ValidateTBEntries
    
    ' Add 8 empty rows to the table
    For i = 1 To 8
    tbl.ListRows.Add
    Next i
    
    ' Find the last row in the table
    lastRow = tbl.ListRows.Count
    
    ' Copy Wall ID value to "Wall ID" column
    If Trim(Me.cmbWallID.Value) <> "" Then
        For i = 0 To 7
            ws.Cells(lastRow - i, tbl.ListColumns("Wall ID").Index).Value = Me.cmbWallID.Value
        Next i
    End If
    
    ' Copy Wall Description value to "Wall Description" column
    If Trim(Me.lstWallDescription.Value) <> "" Then
        For i = 0 To 7
            ws.Cells(lastRow - i, tbl.ListColumns("Wall Description").Index).Value = Me.lstWallDescription.Value
        Next i
    End If
    
    ' Copy values from textboxes to "Joint Length" column
    valuesArray = Array(Me.txtTBBase.Value, Me.txtTBParapet.Value, Me.txtTBRoofWall.Value, _
                        Me.txtTBSlabNBR.Value, Me.txtTBSlabBR.Value, Me.txtTBCorner.Value, _
                        Me.txtTBOpenPerim.Value, Me.txtTBIntWall.Value)
    
    For i = LBound(valuesArray) To UBound(valuesArray)
        ws.Cells(lastRow - i, tbl.ListColumns("Joint Length").Index).Value = valuesArray(i)
    Next i
    
    ' Get username and current date
    username = Environ("USERNAME")
    currentDate = Date
    
    ' Copy username to "Entered By" column
    For i = 0 To 7
        ws.Cells(lastRow - i, tbl.ListColumns("Entered By").Index).Value = username
    Next i
    
    ' Copy date to "Date Entered" column
    For i = 0 To 7
        ws.Cells(lastRow - i, tbl.ListColumns("Date Entered").Index).Value = currentDate
    Next i
    
    ' Clear the combobox and listbox values after copying
    Me.cmbWallID.Value = ""
    Me.lstWallDescription.Clear
    
    ' Clear values in text boxes
    Me.txtTBBase.Value = ""
    Me.txtTBParapet.Value = ""
    Me.txtTBRoofWall.Value = ""
    Me.txtTBSlabNBR.Value = ""
    Me.txtTBSlabBR.Value = ""
    Me.txtTBCorner.Value = ""
    Me.txtTBOpenPerim.Value = ""
    Me.txtTBIntWall.Value = ""
    Me.TBImage.Picture = LoadPicture("")
    
    MsgBox "Data saved successfully.", vbInformation
End Sub

Administrator's note: Please take the time to review our rules. There aren't many, and they are all important. Our guidelines recommend code tags. I have added them for you this time because you are a new member. --6StringJazzer

Originally Posted by jthomp6395

The table is not protected, the cells are not protected

Is the worksheet protected though? If so, you can't add rows to the table.