This article provides troubleshooting steps for VMware Horizon HTML Access.

Troubleshooting common issues

  • Symptoms:
    • When installing the Blast Agent on a 32-bit Windows 7 desktop, the install fails when it tries to start the Blast Agent, and you see the message:

      Service VMware Blast (VMBlast) failed to start. Verify that you have sufficient privileges to start the system services.
    • The event Viewer displays:

      Product: VMware Blast -- Error 1920. Service 'VMware Blast' (VMBlast) failed to start. Verify that you have sufficient privileges to start system services.
    • Both the normal install and installing using Run as administrator fail.
    • When you attempt to start the service manually, you see the message:

      Windows could not start the VMware Blast service on Local Computer
      Error 1068: The dependency service or group failed to start

  • Cause:

    This occurs because the Windows Firewall must be enabled for the installation to succeed.


    Enable and start the Windows Firewall before installing the Blast Agent.
  • Symptoms:
    • VMware Horizon HTML Access to the Desktop fails
    • You see an error message similar to:

      This webpage is not available

      Google Chrome could not load the webpage because xx.xx.xx.xx took too long to respond. The website may be down, or you may be experiencing issues with your Internet connection.

      Where xx.xx.xx.xx is the IP address of the pool desktop.
  • Cause:

    A firewall is blocking TCP port 8443 to your Security Server / Connection Server.


    You must add firewall exceptions for this traffic to allow VMware Horizon HTML Access.

    • Exceptions are not added automatically on Security Servers.
    • Some firewall settings may be locked by Active Directory (AD) policies.
    • If you have verified the firewall rules but the problem persists and the computer is in a safe zone, you can test access to the desktop by temporarily disabling the firewall.
    • The desktop is accessed using TCP port 22443 whether you are using the Blast Secure Gateway or not.
  • Symptoms:
    • The number of desktop sources intermittently changes.
    • You see the HTML Desktop Sources Not Available message, but after a few seconds, desktops are available.
  • Cause:

    A possible cause is that Suspend desktop after client disconnection is specified in the Pool settings.


    Change the Pool settings so that desktops are not suspended.

General troubleshooting

  • Ensure that you can connect to desktops over PCoIP using the VMware Horizon View Client before attempting to configure VMware Horizon HTML Access. This ensures that the base View environment is operational.

    Note: PCoIP connectivity is not required for VMware Horizon HTML Access to function, however, connecting over PCoIP initially ensures that all components are working appropriately.
  • Ensure that VMware Horizon HTML Access is enabled in the Pool settings.

    Note: The type of pool you create is not important; you can use VMware Horizon HTML Access with any type of supported virtual machine-based desktop pool.
  • If using a Security Server, ensure you have enabled the Inbound Rules created for Blast. There are three rules named VMware View Connection Server (Blast-In), one for each Profile of the Windows Firewall.

    To enable the rules:
    1. Click Control PanelSystem and SecurityWindows Firewall.
    2. Click Advanced Settings.
    3. Click Inbound Rules.
    4. Right-click each Blast rule and click Enable.
  • After changing any setting or restarting services, log out of the View Portal</u> and log in again in a new tab or window. Do not reuse an unsuccessful Blast session.
  • In the View virtual desktop, the VMware Blast service must be running. Each time the service starts, it creates an exception on the Windows Firewall to allow the Blast traffic. The service is configured to start automatically after installing the Feature Pack 1 Agent component.

Required ports

When using the Blast Secure Gateway:
  • Browser TCP 8443 > Connection Server TCP 22443 > View Desktop
  • Browser TCP 8443 > Security Server TCP 22443 > View Desktop
When not using the Blast Secure Gateway:
  • Browser TCP 22443 > View Desktop
In all cases:
  • Browser TCP 443 > Connection Server
  • Browser TCP 443 > Security Server

Required features

When using the Blast Secure Gateway:
  • The Remote Experience Agent must be installed in the View Desktop. Install this feature in the parent image, and recompose the pool to ensure all View machines have this installed.
Pool Requirements:
  • In the View Administrator page, edit the pool settings and ensure that the maximum resolution of any one monitor setting must be 1920x1200 or higher so that the View desktop has at least 17.58 MB of video RAM.
  • The VMware Horizon HTML Access setting must be enabled within the pool.
Connection server:
  • You must install the VMware Horizon HTML Access Web Portal on the View Connection server to enable the VMware Horizon HTML Access functionality. For more information, see the Horizon View HTML Access document.

Product limitations

VMware Horizon HTML Access product limitations:
  • No sound in versions prior to 5.3 Feature Pack 1.
  • No clipboard support between the client and desktop in versions prior to 5.3 Feature Pack 1.
  • Mouse pointer does not change when using Internet Explorer browser when performing tasks such as resizing a window within the View Desktop.
  • Keyboard modifier keys and special keys do not function.
  • No USB passthrough.
  • Cannot use Login as current user.
 Related Information