client: Display critical error toast instead of blank screen

Author: eliandoran

src/public/app/desktop.js

@@ -2,15 +2,24 @@ import appContext from "./components/app_context.js";
 import utils from './services/utils.js';
 import noteTooltipService from './services/note_tooltip.js';
 import bundleService from "./services/bundle.js";
+import toastService from "./services/toast.js";
 import noteAutocompleteService from './services/note_autocomplete.js';
 import macInit from './services/mac_init.js';
 import electronContextMenu from "./menus/electron_context_menu.js";
 import DesktopLayout from "./layouts/desktop_layout.js";
 import glob from "./services/glob.js";
 
 bundleService.getWidgetBundlesByParent().then(widgetBundles => {
-    appContext.setLayout(new DesktopLayout(widgetBundles));
-    appContext.start();
+    appContext.setLayout(new DesktopLayout(widgetBundles));    
+    appContext.start()
+        .catch((e) => {
+            toastService.showPersistent({
+                title: "Critical error",
+                icon: "alert",
+                message: `A critical error has occurred which prevents the client application from starting:\n\n${e.message}\n\nThis is most likely caused by a script failing in an unexpected way. Try starting the application in safe mode and addressing the issue.`,
+            });
+            console.error("Critical error occured", e);
+        });
 });
 
 glob.setupGlobs();