Fix cross browser loading screen

Author: CompuIves

packages/app/src/sandbox/status-screen/index.js

@@ -18,7 +18,11 @@ let iframeReference = null;
 
 function changeText(text: string) {
   if (iframeReference) {
-    if (iframeReference.contentDocument) {
+    if (
+      iframeReference.contentDocument &&
+      iframeReference.contentDocument.getElementsByClassName('text') &&
+      iframeReference.contentDocument.getElementsByClassName('text').item(0)
+    ) {
       iframeReference.contentDocument
         .getElementsByClassName('text')
         .item(0).textContent = text;

packages/app/src/sandbox/status-screen/overlay-manager.js

@@ -30,9 +30,9 @@ function createIframe() {
     if (iframe.contentDocument) {
       resolve(iframe);
     } else {
-      document.getElementById('frame').addEventListener('load', () => {
+      document.getElementById('frame').onload = () => {
         resolve(iframe);
-      });
+      };
     }
   });
 }