diff --git a/frontend/src/lib/document/transcription/TranscriptionEditView.svelte.spec.ts b/frontend/src/lib/document/transcription/TranscriptionEditView.svelte.spec.ts
index ec53e911..ad320cd5 100644
--- a/frontend/src/lib/document/transcription/TranscriptionEditView.svelte.spec.ts
+++ b/frontend/src/lib/document/transcription/TranscriptionEditView.svelte.spec.ts
@@ -3,6 +3,7 @@ import { cleanup, render } from 'vitest-browser-svelte';
 import { page, userEvent } from 'vitest/browser';
 import TranscriptionEditView from './TranscriptionEditView.svelte';
 import { createConfirmService, CONFIRM_KEY } from '$lib/shared/services/confirm.svelte.js';
+import { m } from '$lib/paraglide/messages.js';
 
 afterEach(cleanup);
 
@@ -369,4 +370,67 @@ describe('TranscriptionEditView — mark all reviewed', () => {
 			.toBeDisabled();
 		resolveMarkAll();
 	});
+
+	it('shows error message when onMarkAllReviewed callback rejects', async () => {
+		const onMarkAllReviewed = vi.fn().mockRejectedValue(new Error('INTERNAL_ERROR'));
+		renderView({ blocks: [unreviewedBlock1, unreviewedBlock2], onMarkAllReviewed });
+
+		const btnEl = (await page
+			.getByRole('button', { name: /Alle als fertig markieren/ })
+			.element()) as HTMLButtonElement;
+		btnEl.dispatchEvent(new MouseEvent('click', { bubbles: true, cancelable: true }));
+
+		await expect.element(page.getByRole('alert')).toBeInTheDocument();
+	});
+
+	it('clears error when dismiss button is clicked', async () => {
+		const onMarkAllReviewed = vi.fn().mockRejectedValue(new Error('INTERNAL_ERROR'));
+		renderView({ blocks: [unreviewedBlock1, unreviewedBlock2], onMarkAllReviewed });
+
+		const btnEl = (await page
+			.getByRole('button', { name: /Alle als fertig markieren/ })
+			.element()) as HTMLButtonElement;
+		btnEl.dispatchEvent(new MouseEvent('click', { bubbles: true, cancelable: true }));
+		await expect.element(page.getByRole('alert')).toBeInTheDocument();
+
+		const dismissEl = (await page
+			.getByRole('button', { name: m.comp_dismiss() })
+			.element()) as HTMLButtonElement;
+		dismissEl.dispatchEvent(new MouseEvent('click', { bubbles: true, cancelable: true }));
+
+		await expect.element(page.getByRole('alert')).not.toBeInTheDocument();
+	});
+
+	it('clears error on next successful markAllReviewed call', async () => {
+		const onMarkAllReviewed = vi
+			.fn()
+			.mockRejectedValueOnce(new Error('INTERNAL_ERROR'))
+			.mockResolvedValue(undefined);
+		renderView({ blocks: [unreviewedBlock1, unreviewedBlock2], onMarkAllReviewed });
+
+		const btnEl = (await page
+			.getByRole('button', { name: /Alle als fertig markieren/ })
+			.element()) as HTMLButtonElement;
+		btnEl.dispatchEvent(new MouseEvent('click', { bubbles: true, cancelable: true }));
+		await expect.element(page.getByRole('alert')).toBeInTheDocument();
+
+		btnEl.dispatchEvent(new MouseEvent('click', { bubbles: true, cancelable: true }));
+
+		await expect.element(page.getByRole('alert')).not.toBeInTheDocument();
+	});
+
+	it('re-enables button after markAllReviewed failure', async () => {
+		const onMarkAllReviewed = vi.fn().mockRejectedValue(new Error('INTERNAL_ERROR'));
+		renderView({ blocks: [unreviewedBlock1, unreviewedBlock2], onMarkAllReviewed });
+
+		const btnEl = (await page
+			.getByRole('button', { name: /Alle als fertig markieren/ })
+			.element()) as HTMLButtonElement;
+		btnEl.dispatchEvent(new MouseEvent('click', { bubbles: true, cancelable: true }));
+		await expect.element(page.getByRole('alert')).toBeInTheDocument();
+
+		await expect
+			.element(page.getByRole('button', { name: /Alle als fertig markieren/ }))
+			.not.toBeDisabled();
+	});
 });