Skype for Business Server 2015 CU12 Released – Important Changes & Prerequisite Troubleshooting

Microsoft have released the CU12 cumulative update for Skype for Business Server 2015, and with it, some huge changes.

In addition to the usual bug fixing, they’ve also taken the stance that they won’t be investing any further effort into the Skype for Business Online PowerShell module, instead you MUST use the Microsoft Teams PowerShell module.

To support this, Microsoft automatically uninstalls the Skype for Business Online PowerShell module, but you must install the Microsoft Teams PowerShell module manually.

Update: 23/09/2021 – Changed some language to better clarify the Skype for Business Online module is being removed, not the traditional Skype for Business module.

Microsoft Teams PowerShell Module – Requirements

As part of the migration to utilising the Microsoft Teams PowerShell module, Microsoft have had to adopt the prerequisites from this module. As a result, the following are requirements for Skype for Business Server 2015 CU12 and likely will be for Skype for Business Server 2019 CU6 when it becomes available.

  • .NET 4.7.2 is now the minimum version required, with .NET 4.8 being the recommended build. (Find the version of .NET you have installed here)
  • PowerShell 5.1 (Download for Windows Server 2012 R2 and older from here)

You can see the version of PowerShell you have installed by running the following command:


You can find all the latest update information for Skype for Business Server from Microsoft here.

Issues installing Microsoft Teams Module? Read on!

Microsoft have unfortunately not made the deployment of the Microsoft Teams module as smooth as possible, as at the time of writing 2.3.2 is the minimum version, however it’s only available as a preview. I’ve seen this cause multiple problems with older systems, let’s jump through them.

Cannot process argument transformation on parameter ‘RequiredVersion’. Cannot convert value “2.3.2-preview” to type “System.Version”.

If you receive the above error message, your command isn’t necessarily wrong. Unfortunately this means that you’ve never upgraded your PowerShellGet module. doesn’t support the -AllowPreRelease, this feature was introduced in 1.6.0. As PowerShellGet isn’t installed via the Install-Module command you can’t run Update-Module either, instead to upgrade PowerShellGet you need to run the following command:

Install-Module PowerShellGet -Force

Now you can proceed to install the Microsoft Teams module as normal.

WARNING: Unable to download from URI ‘’

PowerShell doesn’t default to TLS 1.2, whereas the PowerShell Gallery like most things, requires TLS 1.2. This can be resolved by running the following command from PowerShell.

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

Disable-CsMeetingRoom already exists

Microsoft will require you to run this command when installing the new Microsoft Teams module:

Install-Module -Name MicrosoftTeams -RequiredVersion 2.3.2-preview -AllowPrerelease

But if you receive an error message that the command “Disable-CsMeetingRoom” already exists then you’ll have to run this command:

Install-Module -Name MicrosoftTeams -RequiredVersion 2.3.2-preview -AllowPrerelease -AllowClobber

This will allow you to install the new module side-by-side with any other modules that also utilise the same names for commands.

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