Message Box API Errors in Calculate Method

The usage of a MessageBox in the Calculate method results in an error.

 29/03/2024 07:57:42.055 Error MessageBox Error Test, EURAUD, m1 Crashed in Calculate with InvalidOperationException: Operation is not valid due to the current state of the object.

       public override void Calculate(int index)
        {
            if(IsLastBar && _index != index)
            {
                MessageBox.Show("hello");
            }
        }