Unable to edit the settings of the template in vCenter Server 4.1

Error message: Call "PropertyCollector.RetrieveContents" for object "propertyCollector" on vCenter Server "" failed.

Solution: 

To workaround this issue, try removing the virtual machine from inventory and then add it back to the inventory.

Alternatively, connect the vSphere Client directly to the ESX/ESXi host and edit the settings from the vSphere Client.

To remove the virtual machine from inventory and to re-register it: 

1. Power off the virtual machine.
2. Note the ESX/ESXi host on which the virtual machine resides.
3. Right-click the virtual machine and click Remove from Inventory.
4. 
   

   Browse the datastore and locate the virtual machine.
5. 
   

   
   

   Right-click the .vmx file and click Add to Inventory.
6. If you are unable to add the virtual machine, close the vSphere Client from vCenter Server.
7. Log in directly to the ESX/ESXi host on which the virtual machine resides using the vSphere Client. To do this, you must know the root password.
8. Browse the datastore and locate the virtual machine.
9. Right-click the .vmx file and click Add to Inventory.
10. Log in to vCenter Server using the vSphere Client.

Note: You can also use this procedure for a template virtual machine. To do this, convert the template into a virtual machine, remove the virtual machine from inventory, re-register the virtual machine, and then convert it back to a template.
Source: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1025367