VM Web Console is showing white spinning circle on a VM in a DMZ

Products

• VMware vSphere ESXi 8.0

Issue/Introduction

When opening the VM web console, the console page loads but displays only a black screen with a spinning loading icon. The loading indicator persists indefinitely, and no console output is displayed.

Environment

• VMware vSphere ESXi
• VMware vSphere vCenter

Cause

This issue is typically caused by a firewall blocking communication between the workstation and the ESXi host running the virtual machine. In most cases, port 443 is blocked by a network- or host-based firewall.

Starting with vSphere 8.0, port 443 is required to obtain web console tickets. If connectivity on this port is unavailable, access to the VM web console may fail.

Resolution

As a temporary workaround, in environments where port 443 cannot be opened due to security requirements, you may use the following alternative procedure: Activate the VMware Remote Console Proxy (Broadcom login required)

1. Select the vCenter Server on which you would like to enable the web proxy.
2. Navigate to the Configure tab and select Advanced Settings.
3. Click Edit settings on the right side of the page.
4. Use the filter (funnel) icon to search for config.mksdevproxy.enable.
5. If the setting exists and is set to false, change the value to true and save the changes.
6. If config.mksdevproxy.enable does not exist, go to the bottom of the Advanced Settings page, create the setting named config.mksdevproxy.enable, set its value to true, and add the changes.
   
7. Then save the Advanced vCenter Server settings

Note: This workaround is intended only as a temporary measure and should not be considered a permanent solution. It increases the processing load on the vCenter Server and, depending on your environment's size and utilization, may lead to performance issues.