fix setup of new document, closes #966

src/public/app/widgets/mobile_screen_switcher.js

@@ -0,0 +1,15 @@
+import Component from "./component.js";
+
+export default class MobileScreenSwitcherExecutor extends Component {
+    setActiveScreenCommand({screen}) {
+        if (screen !== this.activeScreen) {
+            this.activeScreen = screen;
+
+            this.triggerEvent('activeScreenChanged', {activeScreen: screen});
+        }
+    }
+
+    initialRenderCompleteEvent() {
+        this.setActiveScreenCommand({screen: 'tree'});
+    }
+}