diff --git a/CHANGELOG.md b/CHANGELOG.md
index f49f2b6471e..dc1e8be6293 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -81,6 +81,7 @@ Docs: https://docs.openclaw.ai
 - Agents/Subagents `sessions_spawn`: reject malformed `agentId` inputs before normalization (for example error-message/path-like strings) to prevent unintended synthetic agent IDs and ghost workspace/session paths; includes strict validation regression coverage. (#31381) Thanks @openperf.
 - Webchat/Feishu session continuation: preserve routable `OriginatingChannel`/`OriginatingTo` metadata from session delivery context in `chat.send`, and prefer provider-normalized channel when deciding cross-channel route dispatch so Webchat replies continue on the selected Feishu session instead of falling back to main/internal session routing. (#31573)
 - Pairing/AllowFrom account fallback: handle omitted `accountId` values in `readChannelAllowFromStore` and `readChannelAllowFromStoreSync` as `default`, while preserving legacy unscoped allowFrom merges for default-account flows. Thanks @Sid-Qin and @vincentkoc.
+- Control UI/Legacy browser compatibility: replace `toSorted`-dependent cron suggestion sorting in `app-render` with a compatibility helper so older browsers without `Array.prototype.toSorted` no longer white-screen. (#31775) Thanks @liuxiaopai-ai.
 - Agents/Sandbox workdir mapping: map container workdir paths (for example `/workspace`) back to the host workspace before sandbox path validation so exec requests keep the intended directory in containerized runs instead of falling back to an unavailable host path. (#31841) Thanks @liuxiaopai-ai.
 - Agents/Subagent announce cleanup: keep completion-message runs pending while descendants settle, add a 30 minute hard-expiry backstop to avoid indefinite pending state, and keep retry bookkeeping resumable across deferred wakes. (#23970) Thanks @tyler6204.
 - Gateway/Control UI method guard: allow POST requests to non-UI routes to fall through when no base path is configured, and add POST regression coverage for fallthrough and base-path 405 behavior. (#23970) Thanks @tyler6204.
diff --git a/ui/src/ui/app-render.ts b/ui/src/ui/app-render.ts
index 7bf0665de79..97b2271b1bf 100644
--- a/ui/src/ui/app-render.ts
+++ b/ui/src/ui/app-render.ts
@@ -66,7 +66,7 @@ import {
 import { buildExternalLinkRel, EXTERNAL_LINK_TARGET } from "./external-link.ts";
 import { icons } from "./icons.ts";
 import { normalizeBasePath, TAB_GROUPS, subtitleForTab, titleForTab } from "./navigation.ts";
-import { resolveConfiguredCronModelSuggestions } from "./views/agents-utils.ts";
+import { resolveConfiguredCronModelSuggestions, sortLocaleStrings } from "./views/agents-utils.ts";
 import { renderAgents } from "./views/agents.ts";
 import { renderChannels } from "./views/channels.ts";
 import { renderChat } from "./views/chat.ts";
@@ -166,7 +166,7 @@ export function renderApp(state: AppViewState) {
     state.agentsList?.defaultId ??
     state.agentsList?.agents?.[0]?.id ??
     null;
-  const cronAgentSuggestions = Array.from(
+  const cronAgentSuggestions = sortLocaleStrings(
     new Set(
       [
         ...(state.agentsList?.agents?.map((entry) => entry.id.trim()) ?? []),
@@ -175,8 +175,8 @@ export function renderApp(state: AppViewState) {
           .filter(Boolean),
       ].filter(Boolean),
     ),
-  ).toSorted((a, b) => a.localeCompare(b));
-  const cronModelSuggestions = Array.from(
+  );
+  const cronModelSuggestions = sortLocaleStrings(
     new Set(
       [
         ...state.cronModelSuggestions,
@@ -191,7 +191,7 @@ export function renderApp(state: AppViewState) {
           .filter(Boolean),
       ].filter(Boolean),
     ),
-  ).toSorted((a, b) => a.localeCompare(b));
+  );
   const visibleCronJobs = getVisibleCronJobs(state);
   const selectedDeliveryChannel =
     state.cronForm.deliveryChannel && state.cronForm.deliveryChannel.trim()
diff --git a/ui/src/ui/views/agents-utils.test.ts b/ui/src/ui/views/agents-utils.test.ts
index 56f2cf6ef73..eea9bec03c8 100644
--- a/ui/src/ui/views/agents-utils.test.ts
+++ b/ui/src/ui/views/agents-utils.test.ts
@@ -2,6 +2,7 @@ import { describe, expect, it } from "vitest";
 import {
   resolveConfiguredCronModelSuggestions,
   resolveEffectiveModelFallbacks,
+  sortLocaleStrings,
 } from "./agents-utils.ts";
 
 describe("resolveEffectiveModelFallbacks", () => {
@@ -87,3 +88,13 @@ describe("resolveConfiguredCronModelSuggestions", () => {
     );
   });
 });
+
+describe("sortLocaleStrings", () => {
+  it("sorts values using localeCompare without relying on Array.prototype.toSorted", () => {
+    expect(sortLocaleStrings(["z", "b", "a"])).toEqual(["a", "b", "z"]);
+  });
+
+  it("accepts any iterable input, including sets", () => {
+    expect(sortLocaleStrings(new Set(["beta", "alpha"]))).toEqual(["alpha", "beta"]);
+  });
+});
diff --git a/ui/src/ui/views/agents-utils.ts b/ui/src/ui/views/agents-utils.ts
index 9c3f18c355d..436c5c337c1 100644
--- a/ui/src/ui/views/agents-utils.ts
+++ b/ui/src/ui/views/agents-utils.ts
@@ -288,6 +288,43 @@ function addModelConfigIds(target: Set<string>, modelConfig: unknown) {
   }
 }
 
+export function sortLocaleStrings(values: Iterable<string>): string[] {
+  const sorted = Array.from(values);
+  const buffer = new Array<string>(sorted.length);
+
+  const merge = (left: number, middle: number, right: number): void => {
+    let i = left;
+    let j = middle;
+    let k = left;
+    while (i < middle && j < right) {
+      buffer[k++] = sorted[i].localeCompare(sorted[j]) <= 0 ? sorted[i++] : sorted[j++];
+    }
+    while (i < middle) {
+      buffer[k++] = sorted[i++];
+    }
+    while (j < right) {
+      buffer[k++] = sorted[j++];
+    }
+    for (let idx = left; idx < right; idx += 1) {
+      sorted[idx] = buffer[idx];
+    }
+  };
+
+  const sortRange = (left: number, right: number): void => {
+    if (right - left <= 1) {
+      return;
+    }
+
+    const middle = (left + right) >>> 1;
+    sortRange(left, middle);
+    sortRange(middle, right);
+    merge(left, middle, right);
+  };
+
+  sortRange(0, sorted.length);
+  return sorted;
+}
+
 export function resolveConfiguredCronModelSuggestions(
   configForm: Record<string, unknown> | null,
 ): string[] {
@@ -319,7 +356,7 @@ export function resolveConfiguredCronModelSuggestions(
       addModelConfigIds(out, (entry as Record<string, unknown>).model);
     }
   }
-  return [...out].toSorted((a, b) => a.localeCompare(b));
+  return sortLocaleStrings(out);
 }
 
 export function parseFallbackList(value: string): string[] {