Today, Microsoft released the second ever Windows Server Insider Preview, build 16257. It contains a couple of major new features, such as Delivery Optimization for updates and the Windows Subsystem for Linux.
Oddly, there are no fixes listed, as the list of known issues is much smaller. Here's what's still broken:
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.
Note that only the first two issues listed are new, and the other three were already present in build 16237.
While not related to the build itself, there's a temporary issue that has to do with access to the Windows Server download page for users that have Azure AD accounts. This applies to those that signed up for the Windows Insider Program for Business, which was announced back in February.
Today's build will expire on December 4, and if you want to try it out, you can download it here.