Option Explicit

Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, Cancel As Boolean)
    On Error GoTo exit_
    Cancel = True
    Application.ScreenUpdating = False
    Application.EnableEvents = False
    
    If CheckData Then
        Sh3_Intro.Visible = xlSheetVisible
        Sh3_Intro.Activate
        Sh1_Data.Visible = xlSheetVeryHidden
        Sh2_Tools.Visible = xlSheetHidden
        Me.Save
        Workbook_Open
        Me.Saved = True
    Else
        MsgBox "Не заполнены обязательные столбцы таблицы: C, D, I", vbCritical, "Сохранение отменено"
    End If

exit_:
    Application.EnableEvents = True
    Application.ScreenUpdating = True
    If Err Then MsgBox Err.Description, vbCritical, "Ошибка #" & Err.Number
End Sub

Private Sub Workbook_Open()
    Sh1_Data.Visible = xlSheetVisible
    Sh1_Data.Activate
    Sh2_Tools.Visible = xlSheetHidden
    Sh3_Intro.Visible = xlSheetHidden
End Sub

Private Function CheckData() As Boolean
    Dim Rng         As Range, i&
    
    With Sh1_Data
        Set Rng = .Range("FIO", .Cells(.Rows.Count, .Range("FIO").Column).End(xlUp)).EntireRow
    End With
    
'    If Rng.Rows.Count = 1 Then CheckData = True: Exit Function
    i = Sh1_Data.Evaluate("COUNTA(" & Rng.Columns("C").Address & "," & Rng.Columns("D:I").Address & ")")
    CheckData = Sh1_Data.Evaluate("COUNTA(" & Rng.Columns("C").Address & "," & Rng.Columns("D:I").Address & ")") = Rng.Columns(1).Cells.Count * 4
End Function