add about

.next/app-build-manifest.json

@@ -30,6 +30,11 @@
       "static/chunks/webpack.js",
       "static/chunks/main-app.js",
       "static/chunks/app/login/page.js"
+    ],
+    "/_not-found/page": [
+      "static/chunks/webpack.js",
+      "static/chunks/main-app.js",
+      "static/chunks/app/_not-found/page.js"
     ]
   }
 }