Free ESXi (also known just as vSphere Hypervisor) license does not allow for write operations using any of the remote CLI's which relies on the API. This is an expected behavior and is not an error. For more details, you can take a look at this article that I wrote awhile back regarding the "fault.restrictedversion.summary" http://www.virtuallyghetto.com/2011/06/dreaded-faultrestrictedversionsummary.html
