You’re able to successfully authenticate via the login page for HTML access:
… but notice that launching a virtual desktop will immediately fail with the error message:
This error stumped me for quite some time as I was unable to find any related forum posts or KB articles and what ended up being the issue was that the Google Chrome browser I was using could not launch the desktop:
Version: 66.0.3359.139 64-bit
Attempting to use an alternate browser such as Microsoft Edge successfully launched the virtual desktop:
I proceeded to try using the problematic Google Chrome browser to launch a VMware Horizon View 7.4.0 virtual desktop and was successful so this problem appears to be limited to 6.2.0.