Unity freezes when trying to load GUISkin from Asset Bundle

Hello,

When I try to load a GUISkin form Asset Bundle, Unity freezes and nothing else can be done.
This is the critical line of code that crashes Unity:
var assetLoadRequest = mainMenuAssetBundle.LoadAssetAsync(“MainMenuSkin”);

I have no problems with loading textures from the same asset bundle, the only thing that goes wrong is loading GUISkin. What can cause freezing? Is anyone familiar with this problem?

My problem is similar to @BartoszStochel 's. I am trying to load a scene that uses a custom GUI skin to draw UI from asset bundle. When asset bundle is downloaded and scene is loaded, the UI that uses the custom skin is black.

Can anyone help me in solving this ?