Slider does not respond to changes

Hi all,
I’m newbie in Juce and in VS C++ also, so my question is very simple (I hope).
I trying to follow Tutorial: Create a basic Audio/MIDI plugin, Part 2: Coding your plug-in from here:

The strange thing is that my midiVolume slider has appeared in UI, but it does not responding to changes. It shows popup “1 Volume” when I trying to drag it with mouse pointer but value is not changing and component looks freezed.

I debugged the component’s behaviour and find out that when I click it with mouse, the sliderValueChanged callback method triggered twice. On first time it receives the right value (for example 112) and right after that it receives the default slider’s value = 1. So actually nothing is changed after these two calls.

What I did wrong?

It’s difficult to know.

I’ve just built the tutorial and it’s working as expected for me. Are you doing something in your sliderValueChanged method that changes the value of the slider to 1?