This is code in my action handler:

```
    private async void startButton_Click(object sender, EventArgs e)
    {
        try
        {
            var expression = expressionTextBox.Text;
            var result = await Task.Run(() => Algebra.Divide(expression));
            resultTextBox.Text = result.Polynom.ToString();
        } catch (Exception ex)
        {
            Logger.Error(ex.Message);
            detailsTextbox.BackColor = Color.Red;
            detailsTextbox.AppendText("An error occurred! Please check if your expression is valid.");
        }
    }

```

And in `Algebra.Divide` I only put throwing exception for testing exception scenario:

```
    public static DivisionResult Divide (string expression)
    {
            throw new Exception("Error occured");
    }

```

And here is what happens when I click button:
[![enter image description here](https://i.stack.imgur.com/Eo6lH.png)](https://i.stack.imgur.com/Eo6lH.png)

Why doesn't it propagate exception to action handler where I have try/catch block? I tried also without synchronous call to `Algebra.Divide()` but it is the same error.