SmartObjects - Connection not made

The K2 Data Source (SmartObjectsClient) fails to connect, and displays the following message: 

No connection could be made because the target machine actively refused it.

Solution:

This is due to the K2 Server which did not start. The following actions can be followed to correct this problem:

• Ensure that the K2 Server has started
• Ensure that the correct Service Account permissions have been applied to the K2 Server Service Account
• The K2 Server license might have expired, contact your Regional Support