unexpected error 'ch.dunes.model.sdk.SDKFinderException: convertToResult()

I have implemented the 'Build vCenter Inventory' worflow which is one of workflows presented by VMware's  Brian Watrous in his http://blogs.vmware.com/orchestrator/ presentations.

I am getting the following errors:

(1) Variables tab, Exception:

Unable to convert object, 'Datacenter<datacenter-1965>' plugin exception reason : convertToResult() --> Finder 'VC:Datacenter' : unexpected error 'ch.dunes.model.sdk.SDKFinderException: convertToResult() --> Finder 'VC:Datacenter' : unable to invoke read method : 'name''

(2) Logs, Messages:

2013-04-01 12:04:04.776] [I] Workflow:Create datacenter / Create datacenter (item0) : ch.dunes.model.type.ConvertorException: Unable to convert object, 'Datacenter<datacenter-1965>' plugin exception reason : convertToResult() --> Finder 'VC:Datacenter' : unexpected error 'ch.dunes.model.sdk.SDKFinderException: convertToResult() --> Finder 'VC:Datacenter' : unable to invoke read method : 'name''

Any help on this issue would be greatly appreciated.

How do I need to proceed to troubleshoot the issue? I looked at the vSphere System logs, there are several log files and some of them are huge...

Thanks in advance,