title: Call 'invoke.js 'fails in 'Writing Your First Application' official section
body: <p>every one,</p>
  
  <p>I follow the Hyperledger Fabric v1.2 doc to build the fabcar application.</p>
  
  <p>The network can set up and be queried successfully.
  However, when i calling 'node invoke.js', the following error pops up.</p>
  
  <pre><code>Successfully loaded user1 from persistence
  Assigning transaction_id:  a9a75de658c14f487d8a57b110d472d2b73471e24af0fa95159048ec39ae7242
  Transaction proposal was good
  Successfully sent Proposal and received ProposalResponse: Status - 200, message - ""
  Failed to invoke successfully :: TypeError: fabric_client.newEventHub is not a function
  </code></pre>
  
  <p>From my search on relevant questions, I fix the grpc version to 1.9.1, but didn't resolve it. </p>
  
  <p>This is my updated package.json file.</p>
  
  <pre><code>  1 {
    2     "name": "fabcar",
    3     "version": "1.0.0",
    4     "description": "Hyperledger Fabric Car Sample Application",
    5     "main": "fabcar.js",
    6     "scripts": {
    7         "test": "echo \"Error: no test specified\" &amp;&amp; exit 1"
    8     },
    9     "dependencies": {
   10         "fabric-ca-client": "unstable",
   11         "fabric-client": "unstable",
   12         "grpc": "1.9.1"
   13     },
   14     "author": "Anthony O'Dowd",
   15     "license": "Apache-2.0",
   16     "keywords": [
   17         "Hyperledger",
   18         "Fabric",
   19         "Car",
   20         "Sample",
   21         "Application"
   22     ]
   23 }
  </code></pre>
  
  <p>Any idea to solve this problem? I guess it should be the version problem related. </p>