title: Softlayer API suddenly returned 'Order is missing the following category: Operating System' by flavor provision
body: <p>When I used POST <a href="https://api.softlayer.com/rest/v3.1/SoftLayer_Virtual_Guest.json" rel="nofollow noreferrer">https://api.softlayer.com/rest/v3.1/SoftLayer_Virtual_Guest.json</a>.
  wieh paras:</p>
  
  <pre><code>{
    "parameters": [
      {
        "blockDeviceTemplateGroup": {
          "globalIdentifier": "ea065435-f7ec-4f1c-8f3f-2987086b1427"
        },
        "datacenter": {
          "name": "lon02"
        },
        "dedicatedAccountHostOnlyFlag": false,
        "domain": "softlayer.com",
        "hostname": "test-20171117-034434-485",
        "hourlyBillingFlag": true,
        "localDiskFlag": true,
        "networkComponents": [
          {
            "maxSpeed": 100
          }
        ],
        "primaryBackendNetworkComponent": {
          "networkVlan": {
            "id": 1292651,
            "networkSpace": "PRIVATE"
          }
        },
        "primaryNetworkComponent": {
          "networkVlan": {
            "id": 1292653,
            "networkSpace": "PUBLIC"
          }
        },
        "privateNetworkOnlyFlag": false,
        "supplementalCreateObjectOptions": {
          "flavorKeyName": "BL1_1X2X100"
        }
      }
    ]
  }
  </code></pre>
  
  <p>API returned error: <code>SoftLayer_Exception_Public: Order is missing the following category: Operating System. (HTTP 500)</code></p>
  
  <p>Is is some properties I missed? I verified this method was worked last week.</p>