Was beginning the introduction of Windows Server 2019 to a work environment and ran into some hurdles that were easily cleared, but want to share…
To begin with, you need to have a Volume Licensing agreement with Microsoft. We did and so I jumped into the MS Volume Licensing Service Center (VLSC) portal to grab our Client Specific Volume License Key (CSLVK) Key Management Service (KMS) key.
The CSLVK KMS key is what gets loaded into the KMS server. It’s basically your volume license key that gets hosted internally. The servers and desktops then use a Generic Volume License Key (GVLK) which let the machine know it needs to find and activate against an internal KMS resource and not go out to activate against Microsoft’s servers.
FWIW – you can find all of the GVLK product keys here – https://docs.microsoft.com/en-us/windows-server/get-started/kmsclientkeys
Apparently even if you have the Volume Licensing agreement, MS doesn’t automatically issue the CSLVK KMS key to you in your portal. You actually have to call them, verify some info, and have them generate a key for you which will then show up in your portal. The whole process took just under 5 minutes for me, and I was able to verify that I saw the key in my portal while I was still on the phone with MS.
To contact them I called 1-866-230-0560, option 4, option 1. That got me directly in contact with a representative that was able to issue the key. (Note: Menu options may change, I called in February 2020)
Jumping back into my KMS server, i tried to import the key directly into VAMT, also known as the Volume Activation Management Tool. This failed. I tried a couple more times, I even reinstalled the VAMT tool from the ADK toolkit. Nothing worked. Apparently though, I found out that this is a know issue. https://docs.microsoft.com/en-us/windows/deployment/volume-activation/vamt-known-issues
The workaround was to the slmgr.vbs tool. Entering the command below, allowed it to get added successfully. Replacing <CSVLK> with my actual key issued by MS. After entered, you’ll see a pop-up message stating that the key has been successfully added.
slmgr.vbs /ipk <CSVLK>
Once I had added my CSLVK, I was able to jump back into a new Windows Server 2019 virtual machine that I had created and use the slmgr.vbs command below to successfully activate the new virtual machine against my KMS server.