Add error handlers to catch uncaugth errors

ui/app.js

@@ -284,6 +284,18 @@ function initializeClient() {
     return;
   }
 
+  if (process.env.NODE_ENV === "development") {
+    console.log("Currently in Development environment");
+
+    window.addEventListener("unhandledrejection", function(e) {
+      console.error("Error:", e);
+    });
+
+    window.addEventListener("error", function(e) {
+      console.error("Error:", e);
+    });
+  }
+
   landingRoot.parentNode.removeChild(landingRoot);
 
   let normalRoot = document.createElement("div");