At the same time Microsoft released the Windows Server 2016 Technical Preview 3 bits to MSDN subscribers, they also released the Release Notes on a page on the Microsoft TechNet.
On this page you can view the critical issues, that have currently been identified, that might require avoidance or workaround to get Windows Server 2016 Technical Preview 3 installed and running.
Below is the list with the current important issues for Windows Server 2016 Technical Preview 3:
Using the Install-ADDSForest PowerShell Cmdlet to setup a new Active Directory Domain Services Forest on a Windows Server 2016 installion in Server Core mode might result in unexpected behavior.
If you attempt to start the Edge browser while logged in with the default Administrator account, the browser will fail to open. This is the case whether you start Edge manually, click a help link that loads content using Edge, or generate a report that uses Edge.
To work around this, do any of the following:
Use an account other than the Administrator account. This account can be in the Administrators group, however.
Change the default browser to one other than Edge. You can do this by using Set your default programs in the Programs section of Control Panel
Enable User Access Control for the Administrator account. To do this, start Secpol.msc. Navigate to Local Policies, and then to Security Options. Open User Account Control Admin Approval Mode for the Built-in Administrator account and change the policy to Enabled. Then log out and log in again as Administrator.
In some cases, loading local web content or generated reports might still fail in the Edge browser, regardless of what account you use. If this occurs, load the content in a browser other than Edge. For generated reports that fail to load automatically, open the file manually from its saved location (typically the %temp% folder).
The default settings do not allow file downloads from sites in the Internet Zone even if you turn off enhanced security protection. To work around this, change the security settings to allow file downloads for the relevant network zone.
If you connect to a computer running Windows Server 2016 Technical Preview and have a configuration to allow multiple simultaneous sessions, you will encounter a dialog to choose an existing session instead of logging in to a new session. There is no workaround at this time.
If you configure a Remote Desktop Gateway farm and export the settings as an XML file, the Remote Desktop Gateway Management console on a subsequent server in the farm will not import the settings file. To work around this, manually replicate the settings on the second server.
A number of tasks related to the Windows Shell are not working normally in this release. Some areas known to be affected include (but are not limited to) pinning items to the Start menu, searching from the Start menu, Taskbar icons, System Tray icons, and some Settings pages.
In all known Shell-related issues, you can accomplish the same tasks by other means, such as using Control Panel, the command prompt, or Microsoft Management Console.
The Windows Store shortcut is not present. You cannot access the Universal Store in this release. There is no workaround at this time.
Uninstalling Windows Features and Drivers
In Windows Server 2016 Technical Preview (Server with Desktop Experience), if you uninstall SysWOW64 or Windows PowerShell, the result is Windows Server 2016 Technical Preview in Server Core mode. That is, the entire Desktop Experience feature is removed as well. If this occurs, reinstall Windows Server 2016 Technical Preview (Server with Desktop Experience).
Uninstalling server-drivers-general (by using, for example, Dism /online /disable-feature /featurename:server-drivers-general) is not supported in this release. If you uninstall this feature, you will have to completely reinstall Windows Server.
Upgrades to or from this release are not supported.