diff --git a/apps/desktop/e2e/fixtures.ts b/apps/desktop/e2e/fixtures.ts
index 27a3c0be7c0..93acc6f8623 100644
--- a/apps/desktop/e2e/fixtures.ts
+++ b/apps/desktop/e2e/fixtures.ts
@@ -28,6 +28,7 @@ import * as path from 'node:path'
 import { _electron, type ElectronApplication, type Page } from '@playwright/test'
 
 import { startMockServer } from './mock-server'
+import { installErrorBannerGuard } from './test'
 
 const DESKTOP_ROOT = path.resolve(import.meta.dirname, '..')
 const REPO_ROOT = path.resolve(DESKTOP_ROOT, '..', '..')
@@ -305,6 +306,10 @@ export async function launchDesktop(
 
   const page = await app.firstWindow()
 
+  // Install the error-banner guard so any [role="alert"] that appears
+  // during a test is collected and surfaced in afterEach.
+  installErrorBannerGuard(page)
+
   return { app, page }
 }
 
@@ -514,6 +519,7 @@ export async function setupPackagedApp(): Promise<PackagedAppFixture> {
   })
 
   const page = await app.firstWindow()
+  installErrorBannerGuard(page)
 
   return {
     app,
diff --git a/apps/desktop/e2e/large-session-reload.spec.ts b/apps/desktop/e2e/large-session-reload.spec.ts
index 333a94df2bc..89243f4003d 100644
--- a/apps/desktop/e2e/large-session-reload.spec.ts
+++ b/apps/desktop/e2e/large-session-reload.spec.ts
@@ -27,7 +27,7 @@ import { spawnSync } from 'node:child_process'
 import { readFileSync } from 'node:fs'
 import * as path from 'node:path'
 
-import { _electron, expect, type ElectronApplication, type Page, test } from './test'
+import { _electron, expect, installErrorBannerGuard, type ElectronApplication, type Page, test } from './test'
 
 import {
   buildAppEnv,
@@ -111,6 +111,10 @@ async function setupSeededMockBackend(): Promise<SeededMockBackendFixture> {
   const env = buildAppEnv(sandbox)
   const { app, page } = await launchDesktop(env)
 
+  // Install the error-banner guard on the custom page (launchDesktop
+  // already calls this, but call again in case the page was replaced).
+  installErrorBannerGuard(page)
+
   return {
     app,
     page,
diff --git a/apps/desktop/e2e/test.ts b/apps/desktop/e2e/test.ts
index 1a9fb33225b..4ed4121d3e2 100644
--- a/apps/desktop/e2e/test.ts
+++ b/apps/desktop/e2e/test.ts
@@ -23,8 +23,13 @@ let activePage: Page | null = null
  * Install the error-banner guard on a page. Watches for `[role="alert"]`
  * elements appearing in the DOM. When one is found, records its text
  * content for the afterEach assertion.
+ *
+ * Exported so e2e fixture functions (which create pages via _electron.launch)
+ * can install the guard on their custom pages — the default Playwright `page`
+ * fixture override only catches pages created by Playwright itself, not
+ * pages created by the test's own Electron launch.
  */
-function installErrorBannerGuard(page: Page): void {
+export function installErrorBannerGuard(page: Page): void {
   activePage = page
 
   // Clear any errors from a previous test when a new page is created.
@@ -69,9 +74,10 @@ function installErrorBannerGuard(page: Page): void {
 
 /**
  * Check for error banners that appeared during the test. Called in
- * afterEach via the custom fixture below.
+ * afterEach via the custom fixture below. Also exported so specs that
+ * manage their own page lifecycle can call it directly.
  */
-async function collectErrorBanners(page: Page | null): Promise<string[]> {
+export async function collectErrorBanners(page: Page | null): Promise<string[]> {
   if (!page) {
     return []
   }
@@ -110,12 +116,18 @@ export const test = base.extend({
 })
 
 // afterEach: fail the test if any error banners appeared.
-base.afterEach(async ({ page }, testInfo) => {
-  const errors = await collectErrorBanners(page ?? activePage)
+// Always fires — even if the test already failed for another reason.
+// An error banner often IS the root cause (e.g. "resume failed" from a
+// backend bug), and suppressing it when the test also fails on an
+// assertion hides the real problem.
+//
+// Uses `activePage` (set by installErrorBannerGuard) instead of the
+// default `page` fixture — Electron tests create their own page via
+// app.firstWindow(), so the default `page` fixture is undefined.
+base.afterEach(async ({}, testInfo) => {
+  const errors = await collectErrorBanners(activePage)
 
-  if (errors.length > 0 && testInfo.status !== 'failed') {
-    // Only fail if the test didn't already fail on its own — we don't
-    // want to mask the original assertion error with our banner check.
+  if (errors.length > 0) {
     throw new Error(
       `Error banner(s) appeared during test "${testInfo.title}":\n` +
         errors.map(e => `  • ${e}`).join('\n'),
@@ -123,4 +135,10 @@ base.afterEach(async ({ page }, testInfo) => {
   }
 })
 
+// Reset for the next test file.
+base.afterAll(async () => {
+  seenErrors.length = 0
+  activePage = null
+})
+
 export { expect, type Page, type ElectronApplication, _electron }