Question: I'm trying to change the ActionButton style in UWP's TeachingTip.

A TeachingTip has the following attribute:

```
public Style ActionButtonStyle { get; set; }

```

I was trying to do something like this:

```
mytip.ActionButtonStyle.SetValue(Button.ForegroundProperty, "Red");

```

But it fails with a System.NullReferenceException. I also tried different types of values (Windows.UI.Xaml.Media.Brush and Windows.UI.Color) instead of "Red", but that all failed with the same exception.

I also tried the following:

```
var setter = mytip.ActionButtonStyle.Setters.OfType<Setter>().FirstOrDefault(X => X.Property == Control.ForegroundProperty);
setter.Value = "Red";

```

But that also failed but with a different exception - System.UnauthorizedAccessException

Answer: 
For anyone stumbling into this, and looking for the answer, what I finally did that fixed it is drastically increase the memory my app was getting from kubernetes. it seems it was not an event loop issue but a performance issue. goodluck!
In your worker's module you are using await with promise all,

promise all works asynchronously and await is for synchronous code which blocks the event loop.

you can use await keyword for calling functions which returns promises to work them synchronously

PFA for async/await usage

<https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function>