1. Deploy my attached file(test.php) to server OR create any kind of method that would return a empty body on your backend
2. Create new Unity project
3. Attach user attached script(ExampleClass.cs) to a gameObejct.
3. Play scene

Internal error: Invalid AssetBundle load state - date recompressor is not initialized should pop up in console and Unity should crash afterwards.

I guess when body returned from server is empty, WebRequest is getting stuck and that is causing freeze/crash.

Reproduced with: 5.3.6p2, 5.4.0f3, 5.5.0b5
Not reproduced with: 5.2.0f3(it does not crash, but does not inform user about WebRequest body being empty).