diff --git a/client/portal/src/components/ErrorPage.tsx b/client/portal/src/components/ErrorPage.tsx
index 7a072863..9e37dc02 100644
--- a/client/portal/src/components/ErrorPage.tsx
+++ b/client/portal/src/components/ErrorPage.tsx
@@ -1,7 +1,8 @@
-import { ArrowLeft, Home } from "lucide-react";
+import { ArrowLeft, Home, RefreshCw } from "lucide-react";
 import { isRouteErrorResponse, useNavigate, useRouteError } from "react-router";
 
 import { Button } from "@/components/ui/button";
+import { isChunkLoadError } from "@/shared/lib/stale-chunk-reload";
 
 /**
  * Static rather than the super admin's runtime `contact_email`: this page is
@@ -78,6 +79,9 @@ export function ErrorPage() {
   const error = useRouteError();
   const navigate = useNavigate();
   const { status, label, title, message, detail } = describeError(error);
+  // A missing content-hashed chunk means this tab predates a deploy. Only a
+  // reload fetches the fresh shell; in-app navigation keeps the stale one.
+  const staleBuild = detail != null && isChunkLoadError(detail);
 
   return (
     <main className="zero-login relative isolate flex min-h-svh flex-col overflow-hidden bg-black text-white">
@@ -146,7 +150,19 @@ export function ErrorPage() {
               </div>
             )}
 
-            <div className="mt-6 flex flex-col gap-2.5 sm:mt-7 sm:flex-row">
+            {staleBuild && (
+              <Button
+                className="zero-cut-button mt-6 h-11 w-full bg-[#21FFF0] text-xs font-medium tracking-[0.18em] text-black uppercase shadow-[0_0_20px_rgba(33,255,240,0.28)] hover:bg-[#5cfff4] focus-visible:ring-[#21FFF0]/50 sm:mt-7 sm:h-12"
+                onClick={() => window.location.reload()}
+              >
+                <RefreshCw aria-hidden className="mr-1.5 size-4" />A new version
+                is available — reload
+              </Button>
+            )}
+
+            <div
+              className={`${staleBuild ? "mt-2.5" : "mt-6 sm:mt-7"} flex flex-col gap-2.5 sm:flex-row`}
+            >
               <Button
                 variant="outline"
                 className="zero-cut-button h-11 w-full border-[#21FFF0]/45 bg-transparent text-xs font-medium tracking-[0.18em] text-white uppercase hover:border-[#21FFF0] hover:bg-[#21FFF0]/10 hover:text-white focus-visible:ring-[#21FFF0]/50 sm:h-12 sm:flex-1"
diff --git a/client/portal/src/shared/lib/stale-chunk-reload.ts b/client/portal/src/shared/lib/stale-chunk-reload.ts
index d08243ab..faaac14f 100644
--- a/client/portal/src/shared/lib/stale-chunk-reload.ts
+++ b/client/portal/src/shared/lib/stale-chunk-reload.ts
@@ -5,9 +5,13 @@
  * home-screen PWA that was open before a deploy still holds the previous
  * build's chunk names. The first navigation after the deploy asks the server
  * for a file that no longer exists, the dynamic import rejects, and the router
- * would show the 500 page for what is really "you need the new build". Vite
- * dispatches `vite:preloadError` for exactly that failure; a reload picks up
- * the current shell and its chunks.
+ * would show the 500 page for what is really "you need the new build". A
+ * reload picks up the current shell (served no-cache) and its live chunks.
+ *
+ * Vite dispatches `vite:preloadError` for that failure when the import goes
+ * through its preload helper; imports that bypass it (router lazy loaders,
+ * `import()` inside effects) surface as an unhandled rejection or a global
+ * error instead, so those are watched too.
  *
  * One reload per short window: if the fresh build also fails to load, the
  * problem is not staleness and the error should surface instead of looping.
@@ -15,13 +19,48 @@
 const RELOAD_STAMP_KEY = "harp:stale-chunk-reload";
 const RELOAD_COOLDOWN_MS = 10_000;
 
+const CHUNK_LOAD_ERROR_PATTERNS = [
+  /failed to fetch dynamically imported module/i,
+  /error loading dynamically imported module/i,
+  /importing a module script failed/i,
+  /chunkloaderror/i,
+];
+
+export function isChunkLoadError(message: string): boolean {
+  return CHUNK_LOAD_ERROR_PATTERNS.some((pattern) => pattern.test(message));
+}
+
+function errorMessage(value: unknown): string {
+  if (value instanceof Error) return `${value.name}: ${value.message}`;
+  if (typeof value === "string") return value;
+  return "";
+}
+
+/** Reloads unless a reload already happened within the cooldown window. */
+export function reloadOnce(): boolean {
+  const last = Number(sessionStorage.getItem(RELOAD_STAMP_KEY) ?? 0);
+  if (Date.now() - last < RELOAD_COOLDOWN_MS) return false;
+
+  sessionStorage.setItem(RELOAD_STAMP_KEY, String(Date.now()));
+  window.location.reload();
+  return true;
+}
+
 export function installStaleChunkReload(): void {
   window.addEventListener("vite:preloadError", (event) => {
-    const last = Number(sessionStorage.getItem(RELOAD_STAMP_KEY) ?? 0);
-    if (Date.now() - last < RELOAD_COOLDOWN_MS) return;
+    event.preventDefault();
+    reloadOnce();
+  });
 
-    sessionStorage.setItem(RELOAD_STAMP_KEY, String(Date.now()));
+  window.addEventListener("unhandledrejection", (event) => {
+    if (!isChunkLoadError(errorMessage(event.reason))) return;
     event.preventDefault();
-    window.location.reload();
+    reloadOnce();
+  });
+
+  window.addEventListener("error", (event) => {
+    const message = errorMessage(event.error) || event.message;
+    if (!isChunkLoadError(message)) return;
+    reloadOnce();
   });
 }