If you are using WebMKS for direct console connections with ESXi 6.0 or newer hosted by vCenter 6.0 or newer and your ESXi hosts don’t have CA signed certificates installed, you must add a certificate exception in your browser for vCommander to open a direct console connection. In Chrome and Firefox, the browser will prompt you to add an exception. In Internet Explorer, the browser returns a "There is a problem with this website's security certificate" warning but does not allows you to add an exception. 

You must import the CA Root certificate for your ESXi hosts’ certificates:

  1. Click Continue to this website (not recommended).
  2. Right-click the page background and select Properties.
  3. Click Certificates.
  4. On Certification Path tab, select the CA Root certificate in the Certification path pane and click View Certificate.
  5. Click Install Certificate.
  6. On the Certificate Store page, select Place all certificates in the following store and click Browse.
  7. Enable Show physical stores.
  8. Expand Trusted Root Certification Authorities and select Local Computer.
  9. Once you have completed the Certificate Import Wizard, a security warning is displayed, click Yes.