Can't change label text from another thread

CheckState

Public Class Form1
    Public Problem As ProblemType
    Dim Subscription As String = ""
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.BackgroundImage = My.Resources.wall
    End Sub
    Private Sub Form1_Shown(sender As Object, e As EventArgs) Handles Me.Shown
        Dim T As New Threading.Thread(AddressOf DecryptSub)
        T.IsBackground = False
        T.Start()
        Dim TR As New Threading.Thread(AddressOf CheckState)
        TR.IsBackground = False
        TR.Start()
        'CheckState() is now in Form1, not in Core (the module). This way it worked!
        If My.Settings.Enabled Then
            Me.Invoke(Sub() Me.Label1.Text = "Enabled")
        Else
            Me.Invoke(Sub() Me.Label1.Text = "Disabled")
        End If

    End Sub

End Class

Public Class Form1
    Public Enum ProblemType
        MissingSubscription
        ErrorReadingSubscription
        SubscriptionExpired
    End Enum
    Public Problem As ProblemType
    Dim Subscription As String = ""
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        'Me.BackgroundImage = My.Resources.wall
        'This line of code was present in my original project to change the background of
        ' the form setting a different image in Resources. This is the ONLY line of code I 
        ' have in my original project, so no other operations are done at Form1_Load!
    End Sub
    Private Sub Form1_Shown(sender As Object, e As EventArgs) Handles Me.Shown
        Dim T As New Threading.Thread(AddressOf DecryptSub)
        T.IsBackground = False
        T.Start()
        Dim TR As New Threading.Thread(AddressOf CheckState)
        TR.IsBackground = False
        TR.Start()
    End Sub
End Class

Module Core
    Public MainPath As String = My.Application.Info.DirectoryPath & "\License\Lic.lic"
    Public Sub DecryptSub()
        If My.Computer.FileSystem.FileExists(MainPath) Then
            Try
                'A class to decrypt and encrypt files using SHA. I've not included the code
                'cause I don't think it is relevant...
                'Dim Encrypt As New Encriptor
                'Subscription = Encrypt.DecryptFiles(MainPath)
            Catch ex As Exception
                Form1.Problem = Form1.ProblemType.MissingSubscription
                'LogEntry("Could not find subscription file.", MessageType.Failure)
            End Try

        End If
    End Sub
    Public Sub CheckState()
        'Here I have two different scenarios:
        'FIRST ONE:
        'If My.Settings.Enabled Then
        '    Form1.Label1.Text = "Enabled"
        'Else
        '    Form1.Label1.Text = "Disabled"
        'End If
        'No exceptions are thrown, but as you can see, the program does nothing and
        'the value of the Label remains "Value goes here!"



        'Second One:
        'If My.Settings.Enabled Then
        '    Form1.Invoke(Sub() Form1.Label1.Text = "Enabled")
        'Else
        '    Form1.Invoke(Sub() Form1.Label1.Text = "Disabled")
        'End If
        '
        'I get this exception:
        '
        'System.InvalidOperationException was unhandled
        'HResult = -2146233079
        '  Message=Impossibile chiamare Invoke o BeginInvoke su un controllo finché non viene creato un handle di finestra.
        '        Source = System.Windows.Forms
        'StackTrace:
        '       in System.Windows.Forms.Control.MarshaledInvoke(Control caller, Delegate method, Object[] args, Boolean synchronous)
        '       in System.Windows.Forms.Control.Invoke(Delegate method, Object[] args)
        '       in System.Windows.Forms.Control.Invoke(Delegate method)
        '       in thread1.Core.CheckState() in Z:\desktop\thread1\thread1\Core.vb:riga 32
        '       in System.Threading.ThreadHelper.ThreadStart_Context(Object state)
        '       in System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
        '       in System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
        '       in System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
        '       in System.Threading.ThreadHelper.ThreadStart()
        'InnerException:

    End Sub
End Module