Not sure if you're still experiencing issues, but I've recently embarked upon the HTML5 console journey and happened across this thread. From your first image, it looks like you're using the wrong type of ticket in the URL, but then in your second image, it looks like you have the correct ticket, but you should try including the port with the host, like:

wss://srv-sdesx2.onbase.net:443/ticket/{ticket_string}

Actually, the AcquireTicket page should tell you what port to use.

The problem I'm having with all of this is that the wmks approach only seems to work with ESXhost IPs, and I am trying to expose the console to external parties, so ESXhost IPs are pointless. I investigated another method, whereby I emulate the URL that vSphere Web Client generates for the built-in web console, which are in the format:

https://{host}:9443/vsphere-client/webconsole.html?vmId={vm_moId}&vmName={vm_name}&serverGuid={server_guid}&locale=en_US&host={host}:443&sessionTicket={AcquireCloneTicket_output}&thumbprint={ssl_thumbprint_from_sessionTicket}

However, as of vSphere 6.0, it seems that the Single Sign On (SSO) page is forced in between, so while I am able to craft the URL perfectly, once you click on the link the SSO page jumps in front and you must login to get to the web console.

If anyone knows of another approach, I'd be much appreciated.