disposing correctly

Viewer/src/model/viewerModel.ts

@@ -289,6 +289,10 @@ export class ViewerModel implements IDisposable {
     }
 
     public dispose() {
+        this.onAfterConfigure.clear();
+        this.onLoadedObservable.clear();
+        this.onLoadErrorObservable.clear();
+        this.onLoadProgressObservable.clear();
         if (this.loader && this.loader.name === "gltf") {
             (<GLTFFileLoader>this.loader).dispose();
         }

Viewer/src/viewer/viewer.ts

@@ -573,6 +573,8 @@ export abstract class AbstractViewer {
             this.scene.activeCamera.detachControl(this.canvas);
         }
 
+        this.modelLoader.dispose();
+
         this.models.forEach(model => {
             model.dispose();
         });