Display Warning Message when a protected cell has been clicked - vba

Question

Currently I have this code. In Column A, I have a current a "YES" or "No" Selection.
Private Sub worksheet_change(ByVal Target As Range)
If Not Intersect(Target, Range("A:A")) Is Nothing Then
ActiveSheet.Unprotect
If Target = "YES" Then
'Column B to S
For i = 1 To 18
With Target.Offset(0, i)
.Locked = False
.FormatConditions.Add Type:=xlExpression, Formula1:="=ISBLANK(" & Target.Offset(0, i).Address & ")"
With .FormatConditions(.FormatConditions.Count)
.SetFirstPriority
.Interior.ColorIndex = 4
End With
End With
Next i
ElseIf Target = "NO" Then
For i = 1 To 73
With Target.Offset(0, i)
.Value = ""
.Locked = True
.FormatConditions.Delete
End With
Next i
End If
ActiveSheet.Protect
End If
End Sub
Now when the user click the cell in Column T (19), I want to display a warning message to the user that this is not applicable for "Yes" selection.

Answer 1

This seems like it should do the task you are asking.
Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
If Not Intersect(Target, Range("A:A")) Is Nothing Then
On Error GoTo bm_SafeExit
Application.EnableEvents = False
Me.Unprotect
Dim trgt As Range
For Each trgt In Intersect(Target, Range("A:A"))
If LCase(trgt.Value2) = "yes" Then
With trgt.Offset(0, 1).Resize(1, 18)
.Locked = False
With .FormatConditions.Add(Type:=xlExpression, Formula1:="=ISBLANK(B" & trgt.Row & ")")
.Interior.ColorIndex = 4
End With
End With
Else
With trgt.Offset(0, 1).Resize(1, 73)
.Value = vbNullString
.Locked = True
.FormatConditions.Delete
End With
End If
Next trgt
End If
bm_SafeExit:
Application.EnableEvents = True
Me.Protect Userinterfaceonly:=True
End Sub
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Not Intersect(Target, Range("T:XFD")) Is Nothing Then
On Error GoTo bm_SafeExit
Application.EnableEvents = False
Dim trgt As Range
For Each trgt In Intersect(Target, Range("T:XFD"))
If LCase(Me.Cells(trgt.Row, "A").Value2) = "yes" Then
MsgBox "Don't try to put Yes here", vbCritical + vbOKOnly, "Bad Choice"
Me.Cells(trgt.Row, "A").Select
End If
Next trgt
End If
bm_SafeExit:
Application.EnableEvents = True
End Sub
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