Some when you work with legacy system such as vcenter 6.0, you need to have flash player to run the application.
In Windows Server 2016, flash player already included in Internet Explorer, but it not enable by default. If you wish to use the flash player, you may enable it by enter following command in command line
dism /online /add-package /packagepath:”C:\Windows\servicing\Packages\Adobe-Flash-For-Windows-Package~31bf3856ad364e35~amd64~~10.0.14393.0.mum”
Once done, close the Internet Explorer and open it again. Now you should able to use flash. 🙂