Problem

After creating the 2nd Group and its instance in API Gateway, when start the 2nd Instance (2nd Group) this error is thrown and instance does not start:

Unable to start API Gateway
Errorcode Reason
Unable to load /api/management/start/group-6/instance-4 status: 500

FATAL 22/Mar/2016:17:53:16.463 [3acf7720] cannot listen on any address for interface *:8080
ERROR 22/Mar/2016:17:53:16.615 [d6505700] cannot connect to 127.0.0.1:8086: Connection refused
ERROR 22/Mar/2016:17:53:16.616 [d6505700] connection failed from Node Manager on 'jameson' to https://jameson:8086' for URL '/api/monitoring/metrics/summary' and 'GET'

Resolution

2nd instance had the same Services port defined like the 1st one: 8080.

Solution is to delete it and create new one with different port (8081).