Thank you for your purchase and kind words — we really appreciate it!
RAM Disk version 26.1 does fully support Windows Server editions. The change in this version is that it now requires a minimum OS build of 17763, which corresponds to Windows Server 2019 or Windows 10 version 1809. This was necessary because version 26.1 uses newer Windows APIs for driver installation and running drivers from the Driver Store, which are not available in earlier OS builds.
Windows Server 2016 is based on OS build 14393, which predates these APIs. It's also worth noting that Microsoft ended mainstream support for Windows Server 2016 back in January 2022, and the extended support is set to end on January 12, 2027. Microsoft recommends upgrading to Windows Server 2019 or later.
If upgrading your server OS is not an option at this time, you can continue using the previous version of RAM Disk (25.12) on your Windows Server 2016 machine.