Microsoft has now pushed Windows Server Insider Preview Build 16257 to insiders. For accessing the latest Windows Server preview release, you need to register at the Windows Insiders for Business program or the Windows Insider Program.

Below you can read what’s new in this preview build below along with known issues that this build comes with. For installing this build you can go to the official download page and download the ISO.

ISO download link

What’s New in Build 16257 for Server:

Windows Subsystem for Linux (WSL) is available on Windows Server

  • Windows Subsystem for Linux (WSL) is now available on Windows Server along with a compliment of Linux distributions.
  • Test WSL on Windows Server.  WSL runs unmodified Linux (ELF64) binaries natively.  With the additions of WSL you can run node.js, Ruby, Python, Perl, Bash scripts or other tools that expect Linux behaviors, environment, or filesystem-layout, the ability to install and run Linux with WSL expands the tools at your disposal on Windows Server.
  • At this time, WSL does not support persistent Linux services (such as daemons and jobs) as background tasks. To enable WSL and install a Linux distribution, see Enable the Windows Subsystem for Linux and Install a Linux distribution in the Windows Server 2016 Installation Guide on GitHub.
  • Read more in this blog or follow the installation guide to try it out.

Known issues:

  • The background tasks infrastructure service (Bisrv.dll) may cause a system crash because of a null class pointer read error (0xC0000005) or a failfast corrupt list entry (0xC0000409) during a Distributed Component Object Model (DCOM) launch, or because of a critical process bug check (error code 0xC0000409, bug check 0xEF) in the host process for Windows services (Svchost.exe).
  • Calling into the firewall service may hang: Apps that call into the firewall, such apps that use networking, may become unresponsive until the user reboots because of an application hang end-task error (0xCFFFFFFF) in the Windows firewall API library (FirewallAPI.dll), which occurs when the library is blocked on an advanced local procedure call (ALPC) port while attempting to diagnose a connection failure and retrieve information.
  • Cluster Sets: A couple of key functionalities to enable end-to-end testing of Cluster Sets scenarios are not present in this build, so defer all evaluation of this scenario to a future build.
  • Bugcheck during volume creation: A stop error may occur during volume creation in a cluster. The recommended workaround is, after restarting the computer, to delete the volume and try creation again.
  • Bugcheck during volume repair: A stop error may occur during volume repair in a cluster. The recommended workaround is to restart the computer. No corruption or data loss is expected.

Source: Microsoft