Error “The server fault ‘SystemError’ had no message.” when working with a VM

Sometimes when you convert a template to a VM it becomes untouchable. When you edit the settings of an untouchable VM, the following error message appears.

The server fault ‘SystemError’ had no message.
Call "PropertyCollector.RetrieveContents" for object "propertyCollector" on vCenter Server "myVMwareServer.eight02.com" failed.
Useful eh? Luckily, fixing the problem is easy: just unregister and register the VM. To do that, perform the following tasks.

1. Make a note of the datastore that contains the untouchable VM.
2. Unregister the VM from the inventory.
   (right-click on the VM then click Remove from Inventory)
3. Open the datastore and subfolder containing the untouchable VM.
4. Register the VMs .VMX file.
   (right-click on the .VMX file then click ‘Add to Inventory’).

Done! The thing I don’t like about this error is it isn’t reproducible. Ah well, hopefully it is fixed in the Adobe Flex vSphere 5 client.