I was trying to test our products to make sure that they are compatible with Windows Server 2016. And during some testing, I mistakenly thought that I can simply "downgrade" .NET framework from 4.6 to 4. So I removed .NET 4.6 from Roles and from IIS.
Now, I can't install it back using installer (because its part of OS so it is asking me to enable it from role & features). And I can't start server manager (to install role & features) because it needs .Net 4 at minimum.
So I am stuck. Do I have any other option than reinstalling OS ? I have sent so much time testing this system, I would rather not do it if possible.
UPDATE: I already tried .NET installer for older Windows OS but it didn't help.