diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1b1ec3789ae..d169aaec681 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Browser/gateway: ignore Playwright dialog-close races from `Page.handleJavaScriptDialog` so browser automation no longer crashes the Gateway when a dialog disappears before Playwright accepts it. (#40067) Thanks @randyjtw.
 - Ollama: compose caller abort signals with guarded-fetch timeouts for native `/api/chat` streams, so `/stop` and early cancellation still interrupt local Ollama requests that also carry provider timeout budgets. Refs #74133. Thanks @obviyus.
 - Doctor/TTS: migrate legacy `messages.tts.enabled`, agent TTS, channel TTS, and voice-call plugin TTS toggles to `auto` mode during `openclaw doctor --fix`, matching the documented TTS config contract. Thanks @vincentkoc.
 - CLI/logs: fall back to the configured Gateway file log when implicit loopback Gateway connections close or time out before or during `logs.tail`, so `openclaw logs` still works while diagnosing local-model Gateway disconnects. Refs #74078. Thanks @sakalaboator.
diff --git a/extensions/browser/src/browser/runtime-lifecycle.ts b/extensions/browser/src/browser/runtime-lifecycle.ts
index ae63ebb7d55..bb078900318 100644
--- a/extensions/browser/src/browser/runtime-lifecycle.ts
+++ b/extensions/browser/src/browser/runtime-lifecycle.ts
@@ -4,6 +4,7 @@ import { isPwAiLoaded } from "./pw-ai-state.js";
 import type { BrowserServerState } from "./server-context.js";
 import { ensureExtensionRelayForProfiles, stopKnownBrowserProfiles } from "./server-lifecycle.js";
 import { startTrackedBrowserTabCleanupTimer } from "./session-tab-cleanup.js";
+import { registerBrowserUnhandledRejectionHandler } from "./unhandled-rejections.js";
 
 export async function createBrowserRuntimeState(params: {
   resolved: BrowserServerState["resolved"];
@@ -25,6 +26,7 @@ export async function createBrowserRuntimeState(params: {
     resolved: params.resolved,
     onWarn: params.onWarn,
   });
+  state.stopUnhandledRejectionHandler = registerBrowserUnhandledRejectionHandler();
 
   return state;
 }
@@ -39,28 +41,32 @@ export async function stopBrowserRuntime(params: {
   if (!params.current) {
     return;
   }
-  params.current.stopTrackedTabCleanup?.();
-
-  await stopKnownBrowserProfiles({
-    getState: params.getState,
-    onWarn: params.onWarn,
-  });
-
-  if (params.closeServer && params.current.server) {
-    await new Promise<void>((resolve) => {
-      params.current?.server?.close(() => resolve());
-    });
-  }
-
-  params.clearState();
-
-  if (!isPwAiLoaded()) {
-    return;
-  }
   try {
-    const mod = await getPwAiModule({ mode: "soft" });
-    await mod?.closePlaywrightBrowserConnection();
-  } catch {
-    // ignore
+    params.current.stopTrackedTabCleanup?.();
+
+    await stopKnownBrowserProfiles({
+      getState: params.getState,
+      onWarn: params.onWarn,
+    });
+
+    if (params.closeServer && params.current.server) {
+      await new Promise<void>((resolve) => {
+        params.current?.server?.close(() => resolve());
+      });
+    }
+
+    params.clearState();
+
+    if (!isPwAiLoaded()) {
+      return;
+    }
+    try {
+      const mod = await getPwAiModule({ mode: "soft" });
+      await mod?.closePlaywrightBrowserConnection();
+    } catch {
+      // ignore
+    }
+  } finally {
+    params.current.stopUnhandledRejectionHandler?.();
   }
 }
diff --git a/extensions/browser/src/browser/runtime-lifecycle.unhandled-rejections.test.ts b/extensions/browser/src/browser/runtime-lifecycle.unhandled-rejections.test.ts
new file mode 100644
index 00000000000..f189b853870
--- /dev/null
+++ b/extensions/browser/src/browser/runtime-lifecycle.unhandled-rejections.test.ts
@@ -0,0 +1,139 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const { getUnhandledRejectionHandlers, registerUnhandledRejectionHandlerMock, resetHandlers } =
+  vi.hoisted(() => {
+    let handlers: Array<(reason: unknown) => boolean> = [];
+    return {
+      getUnhandledRejectionHandlers: () => handlers,
+      registerUnhandledRejectionHandlerMock: vi.fn((handler: (reason: unknown) => boolean) => {
+        handlers.push(handler);
+        return () => {
+          handlers = handlers.filter((candidate) => candidate !== handler);
+        };
+      }),
+      resetHandlers: () => {
+        handlers = [];
+      },
+    };
+  });
+
+const {
+  ensureExtensionRelayForProfilesMock,
+  getPwAiModuleMock,
+  isPwAiLoadedMock,
+  startTrackedBrowserTabCleanupTimerMock,
+  stopKnownBrowserProfilesMock,
+  trackedTabCleanupMock,
+} = vi.hoisted(() => {
+  const trackedTabCleanupMock = vi.fn();
+  return {
+    ensureExtensionRelayForProfilesMock: vi.fn(async () => {}),
+    getPwAiModuleMock: vi.fn(),
+    isPwAiLoadedMock: vi.fn(() => false),
+    startTrackedBrowserTabCleanupTimerMock: vi.fn(() => trackedTabCleanupMock),
+    stopKnownBrowserProfilesMock: vi.fn(async () => {}),
+    trackedTabCleanupMock,
+  };
+});
+
+vi.mock("openclaw/plugin-sdk/runtime-env", () => ({
+  registerUnhandledRejectionHandler: registerUnhandledRejectionHandlerMock,
+}));
+
+vi.mock("./server-lifecycle.js", () => ({
+  ensureExtensionRelayForProfiles: ensureExtensionRelayForProfilesMock,
+  stopKnownBrowserProfiles: stopKnownBrowserProfilesMock,
+}));
+
+vi.mock("./session-tab-cleanup.js", () => ({
+  startTrackedBrowserTabCleanupTimer: startTrackedBrowserTabCleanupTimerMock,
+}));
+
+vi.mock("./pw-ai-state.js", () => ({
+  isPwAiLoaded: isPwAiLoadedMock,
+}));
+
+vi.mock("./pw-ai-module.js", () => ({
+  getPwAiModule: getPwAiModuleMock,
+}));
+
+const { createBrowserRuntimeState, stopBrowserRuntime } = await import("./runtime-lifecycle.js");
+const { isPlaywrightDialogRaceUnhandledRejection } = await import("./unhandled-rejections.js");
+
+beforeEach(() => {
+  resetHandlers();
+  registerUnhandledRejectionHandlerMock.mockClear();
+  ensureExtensionRelayForProfilesMock.mockClear();
+  getPwAiModuleMock.mockClear();
+  isPwAiLoadedMock.mockReset().mockReturnValue(false);
+  startTrackedBrowserTabCleanupTimerMock.mockClear();
+  stopKnownBrowserProfilesMock.mockClear();
+  trackedTabCleanupMock.mockClear();
+});
+
+describe("browser unhandled rejection lifecycle", () => {
+  it("matches direct and nested Playwright dialog-race protocol errors", () => {
+    const direct = Object.assign(
+      new Error("Protocol error (Page.handleJavaScriptDialog): No dialog is showing"),
+      { method: "Page.handleJavaScriptDialog" },
+    );
+    const nested = new Error("browser action failed", {
+      cause: Object.assign(new Error("No dialog is showing"), {
+        method: "Page.handleJavaScriptDialog",
+      }),
+    });
+    const wrapped = {
+      error: new Error("Protocol error (Dialog.handleJavaScriptDialog): No dialog is showing"),
+    };
+
+    expect(isPlaywrightDialogRaceUnhandledRejection(direct)).toBe(true);
+    expect(isPlaywrightDialogRaceUnhandledRejection(nested)).toBe(true);
+    expect(isPlaywrightDialogRaceUnhandledRejection(wrapped)).toBe(true);
+  });
+
+  it("keeps non-dialog and non-race Playwright errors unhandled", () => {
+    expect(
+      isPlaywrightDialogRaceUnhandledRejection(
+        Object.assign(new Error("No dialog is showing"), { method: "Page.navigate" }),
+      ),
+    ).toBe(false);
+    expect(
+      isPlaywrightDialogRaceUnhandledRejection(
+        new Error("Protocol error (Page.handleJavaScriptDialog): Target closed"),
+      ),
+    ).toBe(false);
+    expect(isPlaywrightDialogRaceUnhandledRejection(new Error("No dialog is showing"))).toBe(false);
+  });
+
+  it("registers during startup and unregisters during shutdown", async () => {
+    stopKnownBrowserProfilesMock.mockImplementationOnce(async () => {
+      expect(getUnhandledRejectionHandlers()).toHaveLength(1);
+    });
+    const state = await createBrowserRuntimeState({
+      resolved: { profiles: {} } as never,
+      port: 18791,
+      onWarn: vi.fn(),
+    });
+
+    expect(registerUnhandledRejectionHandlerMock).toHaveBeenCalledTimes(1);
+    expect(getUnhandledRejectionHandlers()).toHaveLength(1);
+    expect(
+      getUnhandledRejectionHandlers()[0]?.(
+        new Error("Protocol error (Page.handleJavaScriptDialog): No dialog is showing"),
+      ),
+    ).toBe(true);
+
+    const clearState = vi.fn();
+    await stopBrowserRuntime({
+      current: state,
+      getState: () => state,
+      clearState,
+      onWarn: vi.fn(),
+    });
+
+    expect(trackedTabCleanupMock).toHaveBeenCalledTimes(1);
+    expect(stopKnownBrowserProfilesMock).toHaveBeenCalledTimes(1);
+    expect(clearState).toHaveBeenCalledTimes(1);
+    expect(getUnhandledRejectionHandlers()).toEqual([]);
+  });
+});
diff --git a/extensions/browser/src/browser/server-context.types.ts b/extensions/browser/src/browser/server-context.types.ts
index f495a6796bb..0a33bac03bc 100644
--- a/extensions/browser/src/browser/server-context.types.ts
+++ b/extensions/browser/src/browser/server-context.types.ts
@@ -37,6 +37,7 @@ export type BrowserServerState = {
   resolved: ResolvedBrowserConfig;
   profiles: Map<string, ProfileRuntimeState>;
   stopTrackedTabCleanup?: () => void;
+  stopUnhandledRejectionHandler?: () => void;
 };
 
 type BrowserProfileActions = {
diff --git a/extensions/browser/src/browser/unhandled-rejections.ts b/extensions/browser/src/browser/unhandled-rejections.ts
new file mode 100644
index 00000000000..310c330b479
--- /dev/null
+++ b/extensions/browser/src/browser/unhandled-rejections.ts
@@ -0,0 +1,94 @@
+import { registerUnhandledRejectionHandler } from "openclaw/plugin-sdk/runtime-env";
+
+const PLAYWRIGHT_DIALOG_METHODS = new Set([
+  "Page.handleJavaScriptDialog",
+  "Dialog.handleJavaScriptDialog",
+]);
+
+const NO_DIALOG_MESSAGE = "no dialog is showing";
+
+function collectNestedErrorCandidates(err: unknown): unknown[] {
+  const queue: unknown[] = [err];
+  const seen = new Set<unknown>();
+  const candidates: unknown[] = [];
+
+  while (queue.length > 0) {
+    const current = queue.shift();
+    if (current == null || seen.has(current)) {
+      continue;
+    }
+    seen.add(current);
+    candidates.push(current);
+
+    if (!current || typeof current !== "object") {
+      continue;
+    }
+
+    const record = current as Record<string, unknown>;
+    for (const nested of [
+      record.cause,
+      record.reason,
+      record.original,
+      record.error,
+      record.data,
+    ]) {
+      if (nested != null && !seen.has(nested)) {
+        queue.push(nested);
+      }
+    }
+    if (Array.isArray(record.errors)) {
+      for (const nested of record.errors) {
+        if (nested != null && !seen.has(nested)) {
+          queue.push(nested);
+        }
+      }
+    }
+  }
+
+  return candidates;
+}
+
+function readMessage(err: unknown): string {
+  if (typeof err === "string") {
+    return err;
+  }
+  if (!err || typeof err !== "object") {
+    return "";
+  }
+  const message = (err as { message?: unknown }).message;
+  return typeof message === "string" ? message : "";
+}
+
+function readPlaywrightMethod(err: unknown): string | undefined {
+  if (!err || typeof err !== "object") {
+    return undefined;
+  }
+  const method = (err as { method?: unknown }).method;
+  return typeof method === "string" ? method : undefined;
+}
+
+export function isPlaywrightDialogRaceUnhandledRejection(reason: unknown): boolean {
+  for (const candidate of collectNestedErrorCandidates(reason)) {
+    const message = readMessage(candidate);
+    const normalizedMessage = message.toLowerCase();
+    if (!normalizedMessage.includes(NO_DIALOG_MESSAGE)) {
+      continue;
+    }
+
+    const method = readPlaywrightMethod(candidate);
+    if (method && PLAYWRIGHT_DIALOG_METHODS.has(method)) {
+      return true;
+    }
+    for (const playwrightMethod of PLAYWRIGHT_DIALOG_METHODS) {
+      if (message.includes(playwrightMethod)) {
+        return true;
+      }
+    }
+  }
+
+  return false;
+}
+
+export function registerBrowserUnhandledRejectionHandler(): () => void {
+  return registerUnhandledRejectionHandler(isPlaywrightDialogRaceUnhandledRejection);
+}