Cannot register plugin package as vCenter Server

I'm having difficulty deploying and registering my plugin package as an extension to our local vCenter server.  


First, I went thru all the steps in the SDK tutorial to allow my plugin to be deployed to my local Virgo server.  I created the plugin-package.xml, bundled all third party libraries, and was able to deploy my plugin package to the virgo server, eventually without problem.


I next followed instructions to register the plugin package as a vCenter Server extension.  I created the zip file and hosted the plugin zip on our storage server.  I created the extension.xml file, referencing the zip url, but was unable to register the extension.   I tried both Dev test modes to register the plugin, using old Windows vSphere Client (Manage Plug-ins) and using the MOB interface to register an extension.   The plugin appears to register, that is, no errors from the client end, but I do not see my Plugin in the vCenter home extension view where I expect.


Looking at the vSphere client virgo logs, the only relevant entry I could find stated "object with no server guid".  After the user session is logged in, I see the following log:


com.vmware.vise.vim.data.adapters.search.impl.QueryExecutor       object with no server guid: urn:vri:VcExtension:C7EBCA69-C086-4751-92FA-CC0CAC01B58C/com.myCompany.myApp.vSpherePlugin


Any ideas?


Thanks,


Eric