VMWare Horizon Pool options are grayed out: how to edit?

When you create a pool in VMWare Horizon View Administrator console you are able to modify the settings of this pool. However, some options may be grayed out and you would not be able to modify them using the web interface. I ran into that during the re-creation of one of the pool. I have set the option "Allow users to choose protocol" to Yes, while it was required to deny the protocol selection.

I tried to find a way to change this option and noticed the following VMWare forum topic: Cannot change Remote Desktop-Protocol. There is an answer from one of the forum members who described the method to modify pool settings using ADSI editing tool. You will need the following article to be able to connect to ADAM Database of VMWare Horizon View: Connecting to the View ADAM Database (2012377).

Using this article I was able to connect to the ADAM Database and to find the required parameter by comparing its values with the values of another pool. The name of the attribute is pae-ServerProtocolAllowOverride.

However, if you modify this parameter, nothing would happen. In addition, if you modify any parameter using Horizon administrator console, this value will be overridden and set back to 1. I tried to find out how to apply the modification but with no success.

With that out of the way, I decided to use VMWare PowerCLI. It was already installed on the connection server. Please note that you should run it with admin priviledges. After the application start you may list all the available VMWare cmdlets using the following cmdlet:

Get-Command | ? { $_.Source -like "*VMWare*"}

First cmdlet to use is Get-Pool to get the list of the pools in the Horizon View. You may filter the output to 3 columns: pool_id, poolType and allowProtocolOverride:

Get-Pool | ft pool_id,poolType,allowProtocolOverride -autosize

We need to know the poolType field value because we should determine the type of the pool. You may refer to the documentation about the pool types: Pool type settings. We have the incorrect pool with the poolType value set to  SviNonPersistent. That means that we need to use Update-AutomaticLinkedClonePool cmdlet to update the required value:

Get-Pool | ? {$_.pool_id -eq "VDI-POOL-T01" } | Update-AutomaticLinkedClonePool -AllowProtocolOverride $false

This cmdlet provides no output. Now we can verify that the value has been changed by running the previous cmdlet:

We can verify this modification in the ADAM Database:

Also, you may see this modification in the Horizon View administrator web-interface.

You can edit all the settings using VMWare View PowerCLI, even those which are grayed out in the administrator's web-interface. There is no need to try to modify any settings by editing the ADAM Database. To be honest, I don't even know if this is an applicable way to edit settings of any object in your VMWare Horizon View environment.

Update 02/24/2021: Chris Nodak posted a solution related to VMWare Horizon View 7.X here. It seems that some cmdlets are no longer available in PowerCLI for Horizon View 7.X, so you may try to do the following steps:

1. Disable provisioning at the vCenter level.
2. Back up your ADAM database
3. Connected to the ADAM database with ADSI Edit, found the pool in question and modified the Attribute: pae-ServerProtocolAllowOverride from 0 to 1.
4. Close ADSI edit and go back to Horizon admin, then re-enable provisioning.
5. In the pool settings the option will be grayed out, but it should be set to allow the user to change.
6. Change the default for the pool from PCoIP to Blast, and then change it back.
7. Now the end user can choose which protocol they want to use in the Horizon client.