Message "invalid endpoint" returned when trying to start 3scale APIcast

Issue

When I try to start APIcast, it fails with the following Error:

[lua] configuration_loader.lua:137: init(): failed to load configuration, exiting (code 1)
ERROR: /opt/app-root/src/src/resty/http_ng.lua:58: invalid endpoint
stack traceback:
    /opt/app-root/src/src/resty/http_ng.lua:58: in function 'get_request_params'
    /opt/app-root/src/src/resty/http_ng.lua:89: in function 'get'
    ...-root/src/src/apicast/configuration_loader/remote_v2.lua:222: in function 'services'
    ...-root/src/src/apicast/configuration_loader/remote_v2.lua:166: in function 'call'
    /opt/app-root/src/src/apicast/configuration_loader.lua:54: in function 'load'
    /opt/app-root/src/src/apicast/configuration_loader.lua:58: in function 'boot'
    /opt/app-root/src/libexec/boot.lua:6: in function 'file_gen'
    init_worker_by_lua:49: in function <init_worker_by_lua:47>
    [C]: in function 'xpcall'
    init_worker_by_lua:56: in function <init_worker_by_lua:54>