We have been using Workflow actively for a few months, today when wanting to update a workflow we are getting the following errors in Workflow Designer and Manager.

Could not connect to net.tcp://localhost:8085/ManagementService. The connection attempt lasted for a time span of 00:00:01.9990929. TCP error code 10061: No connection could be made because the target machine actively refused it 127.0.0.1:8085. 

We have rebooted, restarted the service, it shows as running - but cannot connect to it?

Any ideas on what to look for on this.  This has been working fine for many months.