If when adding a Windows 10 Key Management Service (KMS) host key (CSVLK) or a Windows Server 2012 R2 for Windows 10 CSVLK into Volume Activation Management Tool (VAMT) 3.1 (version 10.0.10240.0), and you receive the error message; The specified product key is invalid, then this post is intended to help you. In this post, we will identify the possible cause of this error, as well as provide the workaround for the error.

When this error occurs, you’ll receive the following error message:

The specified product key is invalid or is unsupported by this version of VAMT. An update to support additional products may be available online.

This issue occurs because VAMT 3.1 does not contain the correct pkconfig files to recognize this kind of key.

The current known issues with the Volume Activation Management Tool (VAMT), versions 3.0. and 3.1, include:

• VAMT Windows Management Infrastructure (WMI) remote operations might take longer to execute if the target computer is in a sleep or standby state.
• When you open a Computer Information List (CIL) file that was saved by using a previous version of VAMT, the edition information is not shown for each product in the center pane. You must update the product status again to obtain the edition information.
• The remaining activation count can only be retrieved for Multiple Activation Key (MAKs).

The specified product key is invalid when adding CSVLK to VAMT

If you’re faced with this issue, you can try either of the two recommended workarounds presented below to resolve the issue.

1. Do not add the CSVLK to the VAMT 3.1 tool
2. Download and install the approved hotfix for VAMT

Let’s take a look at the description of the procedure involved concerning each of the workarounds.

1] Do not add the CSVLK to the VAMT 3.1 tool

This workaround requires that instead of adding the CSVLK to the VAMT 3.1 tool, use the command below to install a CSVLK on a KMS host to quickly resolve this issue.

 slmgr.vbs /ipk <CSVLK>

In this command, <CSVLK> represents the specific key that you want to install. For more information about how to use the slmgr.vbs tool, see slmgr.vbs options for obtaining volume activation information.

2] Download and install the approved hotfix for VAMT

To download and install the approve hotfix for VAMT, do the following:

On the KMS host computer, perform the following steps:

• Download this hotfix.
• In File Explorer, right-click 485392_intl_x64_zip and extract the hotfix to C:\KB3058168.
• To extract the contents of the update, run the following command:

expand c:\KB3058168\Windows8.1-KB3058168-x64.msu -f:* C:\KB3058168\

• To extract the contents of Windows8.1-KB3058168-x64.cab, run the following command:

expand c:\KB3058168\Windows8.1-KB3058168-x64.cab -f:pkeyconfig-csvlk.xrm-ms c:\KB3058168

• In the C:\KB3058168\x86_microsoft-windows-s..nent-sku-csvlk-pack_31bf3856ad364e35_6.3.9600.17815_none_bd26b4f34d049716 folder, copy the pkeyconfig-csvlk.xrm-ms file.
• Paste this file into the folder location below:

C:\Program Files (x86)\Windows Kits\10\Assessment and Deployment Kit\VAMT3\pkconfig

• Restart VAMT.

That’s it! Any of the workarounds should help with the product key is invalid when adding CSVLK for Windows 10 activation to VAMT 3.1 issue.