Server is fully patched and has been rebooted. It is updated to the newest version I could find and the 2019 volume license pack has been installed. The KMS server has been working fine for Office 2013 and Windows 10. When we try to add the KMS licenses from our VLC account, we receive the error 'The specified product key is invalid, or is unsupported by this version of VMAT.' Our vendor has been of no help, and Microsoft has been of even less then that!
We have installed office2019volumelicensepack_圆4 on the server.
We have a KMS server running on server 2019 datacenter.