Can't register vCenter in vRO 7.3 stand-alone appliance

Trying to setup a new vRO utility stand-alone appliance.  When I register vCenter,  I'm running the Add vCenter workflow.  Any ideas?  Here is the version of the VC pllugin. VC 6.5.0.5471688  the Vcenter is 6.5d

[2017-08-01 19:20:16.815] [E] Workflow:Add a vCenter Server instance / Register vCenter Server instance (item1) : ch.dunes.model.type.ConvertorException: Unable to convert object, 'vcenter1.ss.local' plugin exception reason : convertToResult() --> Finder 'VC:SdkConnection' : unexpected error 'ch.dunes.model.sdk.SDKFinderException: convertToResult() --> Finder 'VC:SdkConnection' : unable to invoke read method : 'instanceUuid''

[2017-08-01 19:20:16.835] [E] Workflow execution stack:

***

item: 'Add a vCenter Server instance/item1', state: 'failed', business state: 'null', exception: 'Unable to convert object, 'vcenter1.ss.local' plugin exception reason : convertToResult() --> Finder 'VC:SdkConnection' : unexpected error 'ch.dunes.model.sdk.SDKFinderException: convertToResult() --> Finder 'VC:SdkConnection' : unable to invoke read method : 'instanceUuid'''

workflow: 'Add a vCenter Server instance' (f246b7b5-fe89-4da5-a640-36ffc6874069)

|  'attribute': name=hostAndPort type=string value=vcenter1.ss.local:443

|  'attribute': name=errorCode type=string value=

|  'attribute': name=serviceUrls type=Array/string value=#{#string#vcenter1.ss.local:443#;#string#https://vcenter1.ss.local:443/pbm#;#string#https://vcenter1.ss.local:443/sms/sdk#}#

|  'attribute': name=certificateImportException type=string value=

|  'input': name=enabled type=boolean value=false

|  'input': name=host type=string value=vcenter1.ss.local

|  'input': name=port type=number value=443

|  'input': name=path type=string value=/sdk

|  'input': name=sessionPerUser type=boolean value=false

|  'input': name=userName type=string value=vUser@ss.local

|  'input': name=password type=SecureString value=__NULL__

|  'input': name=domain type=string value=

|  'input': name=ignoreCertificateWarnings type=boolean value=true

|  'input': name=httpPort type=number value=null

|  'input': name=pbmUrl type=string value=https://vcenter1.ss.local:443/pbm

|  'input': name=smsUrl type=string value=https://vcenter1.ss.local:443/sms/sdk

|  'output': name=newInstance type=VC:SdkConnection value=null

*** End of execution stack.