This may be related to TLS. In firmware 6.0.0 Teradici dropped support for TLS 1.0 we currently only support TLS 1.1 and TLS 1.2. VMware added support for TLS 1.1 and TLS 1.2 in Horizon 6.2.1.
Check your environment to see if you are restricting the version of TLS to 1.0.
What I can confirm for 100% is by deploying a new VCS 7.6 and a new VM running Horizon Agent 7.6 there are no issues connecting from a TERA2 PCoIP zero client running firmware 6.0.or 6.1


Just want to add some additional information here:
The following are the TLS versions supported for different Zero Client firmware versions:
  1. Prior to 4.8.0 firmware, the maximum version of TLS supported was TLS 1.0.
  2. Firmware 4.8.0 to 5.5.1: supported TLS 1.0, TLS 1.1, TLS 1.2
  3. Firmware 6.x only supports TLS 1.1, TLS 1.2
The latest firmware for a Tera1 PCoIP zero client is 4.7.3 and is only available if you open a case with Teradici. Tera1 is End of Life so all firmware has been removed from the support site. All support for TLS 1.0 has been dropped from all of our Products.
If having issues connecting remember to check the VCS, the Security Server and any other appliance in between the zero client and the VM to ensure you have the correct version of TLS.


Hi @Jason Harknett this is interesting and you are not the first to hit this issue. We cannot reproduce this issue in our environment so we suspect it is something else has changed and not just an upgrade of the Horizon View Agent from 7.5 to 7.6.
The message you are getting "View Connection Server communication error" is a fairly generic message from your View Connection Server (VCS) so the zero client is communicating with your VCS.
The message just above it "transition 129 into CONNECT_PROMPT.VDM_LAUNCH" is the start of the user getting their desktop pool or their entitlements.
Since you do not have enhanced logging for session negotiation enable you are probably missing a message stating the session has timed out. This is the issue we are trying to understand why.
Since you have only updated your Agent have you opened an investigation with VMware on this issue and if so what are they saying?


Hi Jerry, VMware told us to do the following but we have to wait for a maintenance window to try it:
Make changes on the Master image as below :


Add or modify this registry value:

HKLM\Software\Teradici\PCoIP\pcoip_admin
Name: pcoip.ssl_protocol
Type: REG_SZ
Value (default): TLS1.0:TLS1.1:TLS1.2



Add or modify this registry value for cipher:

HKLM\Software\Teradici\PCoIP\pcoip_admin
Name: pcoip.ssl_cipher_list
Type: REG_SZ
Value (default): ECDHE-RSA-AES256-GCM-SHA384:AES256-SHA256:AES256-SHA:ECDHE-RSA-AES128-GCM-SHA256:AES128-SHA256:AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:@STRENGTH



Make changes on the connection server’s :


Add or modify this registry value:

HKLM\Software\Teradici\PCoIP\pcoip_admin
Name: pcoip.ssl_protocol
Type: REG_SZ
Value (default): TLS1.0:TLS1.1:TLS1.2



Add or modify this registry value for cipher:

Use a registry editor to configure cipher suites for a Connection Server instance or security server. A GPO is not available for this setting. Add or modify this registry value:

HKLM\Software\Teradici\SecurityGateway
Name: SSLCipherList
Type: REG_SZ
Value (default): ECDHE-RSA-AES256-GCM-SHA384:AES256-SHA256:AES256-SHA:ECDHE-RSA-AES128-GCM-SHA256:AES128-SHA256:AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA256:@STRENGTH


You are both hitting a very similar issue. First I will deal with the Tera1 not connecting - this is due to the fact that the Tera 1 requires TLS 1.0 to connect and VMware dropped support for TLS 1.0 so when you modify the registry to add support for TLS 1.0 back in you can connect. This became an issue when support for TLS 1.0 was dropped. This is documented in many KBs from both VMware and Teradici.
Now for the Tera 2 issue. Teradici dropped support of TLS 1.0 in firmware 6.0.0 and stated in the release notes that support was dropped. If using Horizon View Agent you must run Horizon View 6.2.1 or newer. If in your golden image you restricted TLS support this may explain why you are having an issue. I just finished deploying a new VCS running Horizon 7.6. I spun up a new VM running Horizon View Agent 7.6. I had no issues connecting from a PCoIP zero client running firmware 6.1.0. I used all default settings for the VCS, the Agent and the PCoIP firmware.
My suggestion is for you to try the same as the issue you are experiencing is not a common (widespread) issue. I suspect you have something configured in your environment that is the root cause. Also note that TLS 1.0 support was dropped for a reason.
Let me know how your testing goes.


Management Console 3.1.3 is free up to and including 100 devices.

Management Console 2.5.1 was the last release that you could manage up to and including 2000 devices for free.


I had the same issue and was unable to connect Wyse P20 (Tera1 chips) thinclients to the Horizon View 7.6 Connection server after upgrading from 7.4.

The following changes resolved my issue.

On the connection server, connect to ADSI as per these instructions (only follow step 1 to 5): https://docs.vmware.com/en/VMware-Horizon-7/7.0/com.vmware.horizon-view.upgrade.doc/GUID-FC4B183F-8067-45DE-B528-A35E5B4EA2DB.html

Then change the following attributes of CN=Common,OU=Global,OU=Properties:

pae-ServerSSLSecureProtocols = \LIST:TLSv1.2,TLSv1.1,TLSv1

pae-ServerSSLCipherSuites = \LIST:TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA

-----------

If it hasn't already been done (because of upgrading from a release prior to 7.4), you will still need to enable TLSv1 on the VDI Desktop/Agent by changing the following registry keys:

[HKEY_LOCAL_MACHINE\SOFTWARE\Teradici\PCoIP\pcoip_admin]

"pcoip.ssl_protocol"="TLS1.0:TLS1.1:TLS1.2"

"pcoip.ssl_cipher_list"="ECDHE-RSA-AES256-GCM-SHA384:AES256-SHA256:AES256-SHA:ECDHE-RSA-AES128-GCM-SHA256:AES128-SHA256:AES128-SHA:@STRENGTH"

And also on the security gateway by changing the following registry keys:

[HKEY_LOCAL_MACHINE\SOFTWARE\Teradici\PCoIP]

"pcoip.ssl_protocol"="TLS1.0:TLS1.1:TLS1.2"

[HKEY_LOCAL_MACHINE\SOFTWARE\Teradici\PCoIP\pcoip_admin]

"pcoip.ssl_protocol"="TLS1.0:TLS1.1:TLS1.2"

[HKEY_LOCAL_MACHINE\SOFTWARE\Teradici\SecurityGateway]

"SSLCipherList"="ECDHE-RSA-AES256-GCM-SHA384:AES256-SHA256:AES256-SHA:ECDHE-RSA-AES128-GCM-SHA256:AES128-SHA256:AES128-SHA:@STRENGTH"

"SSLProtocol"="tls1.2:tls1.1:tls1.0"