scene.debugLayer.show throws error

Hi, I'm in the process of updating from 2.4 -> 3.0.7 and our button to show/hide debuglayer doesn't work anymore because the debug layer throws an exception when show() is called.

I saw the InspectorURL points to a preview url: //preview.babylonjs.com/inspector/babylon.inspector.bundle.js

The network tab shows that the script loads

Here is the information in the console regarding the exception

Uncaught ReferenceError: __extends is not defined
    at babylon.inspector.bundle.js:408
    at INSPECTOR (babylon.inspector.bundle.js:408)
    at Object.global (babylon.inspector.bundle.js:408)
    at __webpack_require__ (babylon.inspector.bundle.js:21)
    at Object.<anonymous> (babylon.inspector.bundle.js:49)
    at __webpack_require__ (babylon.inspector.bundle.js:21)
    at babylon.inspector.bundle.js:41
    at babylon.inspector.bundle.js:44
(anonymous) @ babylon.inspector.bundle.js:408
INSPECTOR @ babylon.inspector.bundle.js:408
global @ babylon.inspector.bundle.js:408
__webpack_require__ @ babylon.inspector.bundle.js:21
(anonymous) @ babylon.inspector.bundle.js:49
__webpack_require__ @ babylon.inspector.bundle.js:21
(anonymous) @ babylon.inspector.bundle.js:41
(anonymous) @ babylon.inspector.bundle.js:44
VM14956:61487 

Uncaught TypeError: Cannot read property 'Inspector' of undefined
    at DebugLayer._createInspector (<anonymous>:61487:48)
    at HTMLScriptElement.script.onload (<anonymous>:5607:21)