Has anyone experienced this befo

I have the following code in the Activate event of Sheet1. There is
only one sheet in the workbook.

'
Private Sub Worksheet_Activate()

With ThisWorkbook.Worksheets("Sheet1")

.Unprotect Password:="abc"
.Range("A3").Value = "TestData"
.Protect Password:="abc"

End With

End Sub
'

I get an error message stating that cell A3 cannot be changed as it is
protected, which means that the "unprotect" part did not execute. The
Workbook Open event activates Sheet 1 (see the code further below).

If I execute the sub a second time (since opening the workbook) then
it works fine.

I have also noticed that the error goes away if I introduce a second
sheet and using the Workbook BeforeClose event to activate the second
sheet before the Open event activates Sheet1.

'
Private Sub Workbook_Open()

ThisWorkbook.Worksheets("Sheet1").Activate
ActiveSheet.Range("A12").Activate

End Sub
'