Deployment Scanner returns an error showing: The non-HTTP Activation feature of .NET Framework 3.5 is not enabled

Problem

The error will cause the Enterprise Vault (EV) installation to fail due to the feature not being enabled/present.  

Error Message

The non-HTTP Activation feature of .NET Framework 3.5 is not enabled.

Cause

This error can be returned if the following services are not present on the EV server:

Net.Msmq Listener Adapter
Net.Pipe Listener Adapter
Net.Tcp Listener Adapter 

This can also be due to the below .NET Framework 4.X features being installed. 

Message Queueing (MSMQ) Activation
Named Pipe Activation 
TCP Activation 

This can also be due to unknown corruption within .NET Framework 3.5.

Solution

Remove the unnecessary features of .NET 4.X along with .NET Framework 3.5 Features from the EV server and reinstall the .NET Framework 3.5 Features.

Remove Features  

1. Open Server Manager on the EV server
2. Click on Local Server 
3. From the Manage menu choose Remove Roles and Features
4. Click Next to the Features section
5. Uncheck .NET Framework 3.5 Features and choose Remove Features on the pop-up
6. Expand .NET Framework 4.X Features > WCF Services and uncheck Message Queueing (MSMQ) Activation, Named Pipe Activation, TCP Activation 
7. Click Next to allow the features to be removed and reboot the server

Install .NET Framework 3.5 Features

1. Open Server Manager on the EV server
2. Click on Local Server 
3. From the Manage menu choose Add Roles and Features
4. Click Next to the Features section
5. Check .NET Framework 3.5 Features and ensure all boxes are checked
6. Click Next to install and complete installation 
7. Validate the services are now present and run Deployment Scanner/EV installation