title: Creating Azure VirtualMachineExtension failure
body: <p>I have a Windows Machine that I want to add VM extension using the azure python SDK , I send the following request </p>
  
  <pre><code>{'location': 'westus', 
  'tags': None, 
  'publisher': 'Microsoft.Compute', 
  'virtual_machine_extension_type': 'CustomScriptExtension', 
  'type_handler_version': '1.4', 
  'settings': '{
  "file_uris": ["https://mysite.azurescripts.net/ps_enable_winrm_http.ps1"],
   "command_to_execute": "powershell -ExecutionPolicy Unrestricted -file ps_enable_winrm_http.ps1"}'
  }
  </code></pre>
  
  <p>but what happens is that it gives the following exception </p>
  
  <pre><code>configure virtual_machine '946b4246-a604-4b01-9e6a-09ed64a93bdb' failed with this error : 
  VM has reported a failure when processing extension '13da0dc5-09c0-4e56-a35d-fdbc42432e11'.
  Error message: "Invalid handler configuration. Exiting. 
  Error Message: Expecting state 'Element'.. Encountered 'Text'  with name '', namespace ''. "
  
  More information on troubleshooting is available at https://aka.ms/VMExtensionCSEWindowsTroubleshoot 
  </code></pre>
  
  <p>adding a simple code snippet that I use </p>
  
  <pre><code>vm_extension_name = "{0}".format(uuid4())
  vm_extension_params = {
      'location': location_val,
      'tags': tags_val,
      'publisher': 'Microsoft.Compute',
      'virtual_machine_extension_type': 'CustomScriptExtension',
      'type_handler_version': type_handler_version,
      'auto_upgrade_minor_version': True,
      'settings': json.dumps({
          'fileUris': file_uris,
          'commandToExecute': command_to_execute
       })
  }
  logger.info("sending {0}".format(vm_extension_params))
  </code></pre>
  
  <p>any ideas , should I send something differently or am I missing something from the above request that cause the issue </p>
  
  <p>thanks for the help in advance </p>
  
  <p>Regards,</p>