I am running to much of the same issue... Below is what is being returned...
Exception calling "UpdateServerData" with "0" argument(s): "Argument ''uriTempl
ate' must not be null' cannot be null.
Parameter name: 'uriTemplate' must not be null"
At C:\users\rharber\desktop\modifydrive.ps1:7 char:123
+ ($vm.ExtensionData.Section | where {$_ -is [VMware.VimAutomation.Cloud.Views.
OvfVirtualHardwareSection]}).updateserverdata <<<< ()
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException