VMware Horizon – Troubleshooting “HTML Access – Failed to connect to the Connection Server”

Release date: September 19th 2022

Welcome to my VMware Horizon series. I recently ran into a problem with connecting to Horizon HTML Access, after upgrading the UAG’s, as show below.

When I checked the logs on my Connection Server in the folder: C:\ProgramData\VMware\VDM\logs, I came across this message: (ajp:broker:Request705) Unexpected Origin: https://desktop.frelab.net

After a little googling, it turns out that the culprit behind this error is “Cross Origin Resource Sharing – CORS”, as described by VMware here: Cross-Origin Resource Sharing (CORS) with Horizon 8 and loadbalanced HTML5 access. (85801)

So, after adding both balancedHost and portalHost entries in the locked.properties file under “C:\Program Files\VMware\VMware View\Server\sslgateway\conf” on all connection servers, and reboot’ed these, the problem was solved.

Note to myself: In the future, read the Release Notes a little more carefully before upgrading the UAG’s.

Official VMware Documentation:

Location of Horizon (VDM) log files (1027744)

VMware Horizon planning, deployment etc.

Disclaimer: Every tips/tricks/posting I have published here, is tried and tested in different it-solutions. It is not guaranteed to work everywhere, but is meant as a tip for other users out there. Remember, Google is your friend and don’t be afraid to steal with pride! Feel free to comment below as needed.