Password Sign On - Help, please!!

[BlueValentine]

I am very new to VBA and am stumped! I have an Excel worksheet that I need to have users access by entering a Username and Password. I keep the user names and passwords on another tab in the same file. I am trying to verify that the user name and user password match the list before allowing the user to access the spreadsheet. I am getting "method range of object _global failed" error and I cannot seem to locate the error in my code. Would someone please help? Thank you!

Sub Login_Click()
    Dim Username As Range
    Dim RowNo As Long
    Dim ws3 As Worksheet
    Dim aCell As Range
    
    On Error GoTo ErrorHandler

    If (Range(d4)) = 0 Then
        Range(d4).SetFocus
        MsgBox "Please select your Username"
        Exit Sub
    End If

    If (Range(d5)) = 0 Then
        Range(d5).SetFocus
        MsgBox "Password cannot be empty"
        Exit Sub
    End If

    Application.ScreenUpdating = False

    Set ws3 = Worksheets("Sheet3")
    Username = Range(d4)

    Set aCell = ws3.Columns(1).Find(What:=Username, LookIn:=xlValues, _
    LookAt:=xlWhole, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
    MatchCase:=False, SearchFormat:=False)

    '~~> If match found
    If Not aCell Is Nothing Then
        RowNo = aCell.Row
        If Range(d5) = aCell.Offset(, 1) Then
            FrmMenu.Show
        Else
            MsgBox "Unable to match User Name or User Password, Please try again", vbOKOnly
        End If
    Else '<~~ If not found
        MsgBox "Unable to match User Name or User Password, Please try again", vbOKOnly
    End If
    ws3.Visible = xlSheetVeryHidden
CleanExit:
    Set ws3 = Nothing
    Application.ScreenUpdating = True
    Exit Sub
ErrorHandler:
    MsgBox Err.Description
    Resume CleanExit
End Sub