Getting the message "The console has been disconnected. Close this window and re-launch the console to reconnect" when opening web console from vSphere Client

Products

• VMware vCenter Server

Issue/Introduction

• When opening Web Console from vSphere Client, getting the message "The console has been disconnected. Close this window and re-launch the console to reconnect".
  
  
  
  
• vsphere-ui returned 403 error for /ui/webconsole/authd request.
  
  /vsphere-ui/logs/access/localhost_access_log.txt
  

  127.0.0.1 ###.###.###.### - - [DD/Month/YYYY:HH:MM:SS] "GET /ui/webconsole.html?vmId=vm-#####&vmName=VM_Name&numMksConnections=0&serverGuid=########-####-####-####-########&locale=en-US HTTP/1.1" 200 7323 - 70892746 http-nio-5090-exec-964 0
  127.0.0.1 ###.###.###.### - - [DD/Month/YYYY:HH:MM:SS] "GET /ui/webconsole/authd?vmId=vm-#####&serverGuid=########-####-####-####-######## HTTP/1.1" 403 431 - - http-nio-5090-exec-969 0

  
  
  

Environment

vCenter Server 7.x
vCenter Server 8.x

Cause

This is a browser issue.

This is caused by Firefox (or some browser) not sending the correct origin header and vsphere-ui service rejects requests with null origin header for security reasons.
This usually occurs when there is a proxy involved and websockets over http2 are used.

Resolution

Workaround
Changing network.http.http2.websockets to false in firefox advanced settings.

1. Opening Firefox browser
2. Access about:config
3. Search for websockets and change network.http.http2.websockets setting from true to false
4. Refresh the browser