update faq related to chrome 142

Author: lyzhang0113

_articles/faq/chromium-142-local-network-access-issue.md

@@ -7,78 +7,87 @@ keywords: Dynamic Web TWAIN, Error Troubleshooting, CORS, unknown address space,
 breadcrumbText: Error message - Permission was denied for this request to access the unknown address space
 description: CORS unknown address space
 date: 2025-11-04 17:21:42 +0800
-last_modified: 2025-11-04 17:21:42 +0800
+last_modified: 2025-11-05 17:26:42 +0800
 ---
 
 # Error Troubleshooting
 
 > [!IMPORTANT]
 > This is a newly developing issue, and as such the information in this article may change over time.
 
-## Error message - Access to fetch at `https://127.0.0.1:18623` or `http://127.0.0.1:18622` has been blocked by CORS policy: Permission was denied for this request to access the unknown address space.
+## Error message - CORS Errors caused by local network access permissions when using Chromium 142 and later
 
-### Symptom
+### Overview
 
-When using Chromium-based browsers version 142 or later (released on October 28th, 2025), including Chrome, Edge, Brave, and Opera, the Dynamsoft Web TWAIN Service may fail to function properly:
+Starting in **Chromium-based browsers v142+** (released Oct 28, 2025)—including Chrome, Edge, Brave, and Opera—Dynamsoft Web TWAIN Service may not work as expected due to new local-network security rules.
 
-- Phenomenon 1: the browser prompts users to download the service installer even though it is already installed.
+### Symptoms
 
-![DWT_installer.png](/assets/imgs/DWT_installer.png)
+You may experience one or more of the following:
+
+***1. Service installer repeatedly prompted***
 
-- Phenomenon 2: the initialization succeeds, but scanning or loading images results in blank images.
+The browser prompts you to download/install the service even though it is already installed.
+![DWT_installer.png](/assets/imgs/DWT_installer.png)
 
-Open the browser console (press F12, then go to the Console tab), you should see the following error message:
+***2. Initialization succeeds, but scan/load shows blank images***
 
+The browser console (F12 → Console) shows a CORS rejection similar to:
 ```shell
 Access to fetch at 'https://127.0.0.1:18623/fa/VersionInfo?ts=1761893667670' from origin 'https://your-domain.com' has been blocked by CORS policy: Permission was denied for this request to access the `unknown` address space.
 ```
 
-### Cause
+### Root Cause
 
-In Chromium 142 Google introduced a new [Local Network Access security policy](https://chromestatus.com/feature/5152728072060928). Requests from web pages to local addresses such as 127.0.0.1 or localhost get blocked unless explicit permission is granted.
+Chromium 142 introduces a new [Local Network Access security policy](https://chromestatus.com/feature/5152728072060928) requirement. 
+Requests from web pages to loopback addresses such as `localhost` / `127.0.0.1` are blocked unless the user (or an admin policy) explicitly grants access.
 
-This affects the Dynamic Web TWAIN Service which relies on local services for communication.
+Because Dynamic Web TWAIN communicates with a local service, these restrictions can prevent normal operation.
 
 ### Resolution
 
-***Step 1: (For All End Users)***
-
-- Navigate to your Dynamic Web TWAIN web interface
-
-- Click the lock icon (or settings icon) next to your site URL in the browser’s address bar.
+***1. To Manually Correct This in Chrome***
 
+- Navigate to your Dynamic Web TWAIN page.
+- Click the lock/settings icon in the browser address bar.
 - Ensure that **Local Network Access** is enabled.
 
 ![local-network.png](/assets/imgs/local-network.png)
 
 > [!NOTE]
 > If you're unable to restore functionality after enabling 'Local Network Access,' please contact [Dynamsoft](https://www.dynamsoft.com/contact/).
 
-***Step 2: (For Developers Only)***
+***2. (For Admins) To Apply This Setting Across an Enterprise***
+
+Enterprise administrators can deploy a Chrome and/or Edge policy to set the "Local Network Access" setting to "Allow" for your website.
 
-**Option 1:**
+Please refer to: 
+* [Chrome Enterprise Policy List & Management Documentation](https://chromeenterprise.google/policies/#LocalNetworkAccessAllowedForUrls)
+* [Microsoft Edge Browser Policy Documentation](https://learn.microsoft.com/en-us/deployedge/microsoft-edge-browser-policies/localnetworkaccessallowedforurls)
 
-You can check the permission programmatically:
+***3. Developer Notes***
+
+**a) Check Permission Programmatically**
 
 ```javascript
 let status = await navigator.permissions.query({ name: "local-network-access" });
 console.log(status.state);
 ```
 
-If the permission is not granted, prompt users to manually enable it (Chrome settings → Privacy and security → Site settings → Local network access).
+If not granted, guide users to:
+
+Chrome → Settings → Privacy and Security → Site Settings → Local network access
+
+**b) If Running Inside an `iframe`**
 
-> [!WARNING]
-> If Dynamic Web TWAIN is running in an iframe, ensure the iframe element includes the following attribute:
+> [!IMPORTANT]
+> If your site is embedded in an iframe, you MUST explicitly allow local-network access.
 
+Please explicitly allow `local-network-access` in the attributes of the iframe:
 ```html
 <iframe src="..." allow="local-network-access *"></iframe>
 ```
 
-**Option 2: (For Enterprise Users)**
-
-Enterprise administrators can allow specified URLs to access local resources through Chrome’s Enterprise Policy configuration.
-Refer to: [Chrome Enterprise Policy List & Management | Documentation](https://chromeenterprise.google/policies/#LocalNetworkAccessAllowedForUrls)
-
-### Planning
+### Roadmap
 
 Dynamsoft plans to add a feature that automatically detects local service connectivity and permission status. If the connection is blocked, users will be prompted with a message and directed to this FAQ page.

_articles/faq/index.md

@@ -206,7 +206,7 @@ description: Dynamic Web TWAIN SDK Documentation FAQ
 30.  [How to debug on Dynamic Web TWAIN online demo?](/_articles/faq/debug-on-online-demo.md)
 31.  [Dynamic Web TWAIN prompts the .deb installer for Windows](/_articles/faq/incorrect-installer-for-windowsARM64.md)
 32.  [Why am I unable to load the TIFF file into Dynamic Web TWAIN?](/_articles/faq/unable-to-load-4-bit-tiff.md)
-33.  [Error message - Permission was denied for this request to access the unknown address space](/_articles/faq/chromium-142-local-network-access-issue.md)
+33.  [Error message - CORS Errors caused by local network access permissions when using Chromium 142 and later](/_articles/faq/chromium-142-local-network-access-issue.md)
 
 ## Licensing and Purchase