In the Performance Monitor, Under the UC4.Decision.EventBaseWriter (MyWorker) section, the Monitor was showing 0 Processed Events, but tens of thousands of Processed Events with Failure.
In the Worker log (Located in Runtime\Worker\logs\UC4.Decision.Worker.log), the following error was observed:
System.Data.SqlClient.SqlException (0x80131904): MSDTC on server 'server name' is unavailable.
Distributed Transaction Coordinator (local Windows Service) was not started.
Navigate to "Services" via:
Control Panel -> Administrative Tools -> Services
Find "Distributed Transation Coordinator" in the list
Right click -> Start
You will have to re-start your Database for this to take effect.