Local Network Access permissions in Chrome and Edge

Starting with Chrome version 142, Google introduced a new Local Network Access (LNA) permission model. This update affects Chrome and Edge browsers.

• When a website or web application tries to access resources on your local network (e.g., localhost, 127.0.0.1, or private IP ranges), the browser now prompts the user for permission.
• This is a security enhancement designed to prevent unauthorized web pages from interacting with local devices or services without user consent.

How Does This Affect VertiGIS Studio Users?

VertiGIS Studio apps often involve services on a local network, such as:

• Web maps referencing ArcGIS Server hosted on a local machine.
• Workflows, custom widgets or tools using internal endpoints for geoprocessing or printing.

If these maps or apps are shared publicly but still make calls to local resources, users will now see a popup asking to allow local network access.
If the user denies access, local services may fail to load (layers may not display, printing may break).

On the browser console, a CORS error will appear:

The text of this error will be: Access to fetch at 'RESOURCE_URL' from origin 'ORIGIN_URL' has been blocked by CORS policy: Permission was denied for this request to access the `local` address space. 

Quick Fix for Individual Users

Users can grant permission for a specific site:

1. Open the web app in Chrome.
2. Click the menu icon in the address bar.
3. Find Local network access and toggle it ON.
   (See screenshot below for reference.)

This setting is per-site and per-user, so each user must enable it manually. Clearing site data or resetting permissions will remove this grant.

If Local Network Access is not visible in the menu, you can find it by clicking Site Settings and then locating the Local Network dropdown. If it is set to Deny, then update the setting to Allow.