Configure the client browser to resolve common errors in Symantec Web Isolation
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Configure the client browser to resolve common errors in Symantec Web Isolation


Article ID: 172654


Updated On:


Web Isolation


End users that use Mozilla Firefox, Google Chrome, or Microsoft Edge cannot access any isolated websites when Symantec Web Isolation has been deployed.

Instead of returning the isolated page, the browser displays an empty page or one of the following messages:

  • “There is no access to the localstorage, Please contact your system administrator”
    There is no access to the localstorage. Please contact your system administrator

  • "No detailed diagnostics were found."
    No detailed diagnostics were found
  • "Isolation server is probably down"

Isolation server is probably down


The browser cannot access one of the following resources:

  • The shared domain
  • Cookies or the local storage


Provide Access to the Shared Domain

The "shared domain" URLs are:


Provide access to shared domain URLS:

  1. Open both URLs directly in the user's browser.
  2. Make sure that they load normally and that you do not see a certificate warning or a proxy notification or lock page. When the page finishes loading, it should be blank.

    If the following message appears, the URL is not being forwarded to the Web Isolation gateways.

     This website should never be accessed directly... You probably did something wrong.
    Forwarding to the Web Isolation gateways is required. When you integrate Web Isolation with an Edge SWG (ProxySG) appliance, the content policy language (CPL) provided by the wizard configures this URL forwarding.


Provide Access to Browser Cookies or LocalStorage

Access to cookies or LocalStorage can be blocked due to browser privacy extensions or browser settings. Perform the following steps to resolve the issue.

Check Browser Extensions

Browser privacy extensions commonly have an option to disable third-party cookies or LocalStorage access, or to enable them as allowed URLs.

  1. Identify the privacy extensions that are enabled in the browser.
  2. Disable all of the extensions and have the user access an isolated website.
  3. If the issue no longer occurs, re-enable extensions one by one to determine which one is causing the issue. Then, configure the extension as required to allow access to cookies/LocalStorage.
    If the issue still occurs after you disable all extensions, reconfigure the browser. See the following section.

Configure the Browser

Follow the appropriate steps to configure the user's browser.

Firefox DOM Storage

  1. Open Firefox.
  2. In the address bar, type about:config and press Enter.
  3. Click I accept the risk!
  4. In the about:config page, search for the entry. The default value for this entry is “true”. If the listed value is “false”, double-click to change the value to “true”.

Firefox Third-Party Cookies

  1. Open Firefox.
  2. Click the hamburger icon at the top-right of the browser.
  3. Click Settings.
  4. Select Privacy & Security in the menu bar on the left.
  5. Select Browser Privacy > Enhanced Tracking Protection.
  6. Select Custom.
  7. Under Cookies, select "Cross-site tracking cookies".


  1. Open Chrome.
  2. In the address bar, type chrome://settings and press Enter.
  3. Click Advanced.
  4. Under Privacy and Security, click Site Settings.
  5. Under Site Settings, click Cookies.
  6. Make sure "Allow sites to save and read cookie data" is enabled.
  7. Make sure "Block third-party cookies" is disabled.


  1. Open Edge.
  2. Click the "..." button in the upper right.
  3. Click Settings.
  4. Click Privacy & Security.
  5. Make sure the Cookies setting is set to "Don't block cookies".