Symptom:

Since the updates of Google Chrome and Microsoft Edge starting from version 147.x.x and Mozialla Firefox starting from version 153.x.x, it may happen that signature pads are no longer detected in web applications or that no connection can be established.


Cause: 

The browsers have introduced new security mechanisms (Local Network Access / Private Network Access).
These prevent websites from automatically accessing local services (e.g. signature pads via localhost/WebSocket).
  • Websites must now be explicitly allowed by the user
  • Without permission, the connection will be blocked
  • this also affects WebSockets (e.g. pad communication)
Background:
This change is intended to protect against attacks on local devices (e.g. routers or other local services).
Important:
This behavior only occurs starting from version 147.


Solution:


Solution 1: Central configuration via Group Policy (recommended)

We recommend configuring this centrally via GPO in enterprise environments.


Microsoft Edge
Registry path:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Edge\LocalNetworkAccessAllowedForUrls
Value:
Google Chrome
Registry path:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Google\Chrome\LocalNetworkAccessAllowedForUrls
Value:

Mozilla FireFox

Registry path:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Mozilla\FireFox\LocalNetworkAccess

Value:

  • Name: Enabled
  • Type: REG_SZ
  • Data: 1

Registry path:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Mozilla\FireFox\LocalNetworkAccess\SkipDomains

Value:


Note:
  • For on-premise installations, you must enter your own server URL instead of universal.signosign.com
  • A browser or system restart may be required after applying the changes
  • Firefox uses domain names (not full URLs with https://) in the skip list 

Solution 2: Reset and re-allow website permissions (for single workstations)

Permissions can also be granted manually for individual users.

Google Chrome
  1. Open Chrome
  2. Enter in the address bar:
    chrome://settings/content/all
  3. Search for the affected website
  4. Open the entry and select “Clear data”
  5. Reload the website
  6. Allow all permission prompts
Alternatively:
  • Click the lock icon in the address bar
  • Open “Site settings”
  • Set “Local network” to “Allow”
Microsoft Edge
  1. Open Edge
  2. Enter in the address bar:
    edge://settings/content/all
  3. Search for the website
  4. Select “Clear data”
  5. Reload the website
  6. Allow all security prompts


Mozilla Firefox

  1. Open Firefox
  2. Enter in the address bar:
    about:preferences#privacy
  3. In the left-hand navigation, go to "Permissions and Data"
  4. Click the "Device apps and services" entry
  5. Allow the website
  6. Allow all permission request(s) that appear

Alternatively:

  • Click the lock/permissions icon in the address bar
  • Reset the permissions directly