title: What is the reason of this error in ansible 2.7.10 - "ERROR! playbook entries must be either a valid play or an include statement|"
body: <p>I am watching a tutorial of Ansible where I have to deploy a playbook. The play-book code are following:</p>
  
  <pre><code>- name:"Do a demo"
    hosts:groupA
  
    tasks:!!seq
      - name:demo task 1
        debug:!!seq
          msg:"this is task 1"
  
      - name:demo task 2
        debug:!!seq
          msg:"this is task 2"
  
  - name:"Do another demo"
    hosts:groupB
  
    tasks:!!seq
      - name:demo task 3
        debug:!!seq
        msg:"this is task 3"
  
      - name:demo task 4
        debug:!!seq
          msg:"this is task 4"
  </code></pre>
  
  <p>When I tried to deploy the above play-book using <code>ansible-playbook -i hosts demoplays.yaml</code> command, the error was raised:-</p>
  
  <pre><code>ERROR! playbook entries must be either a valid play or an include statement
  
  The error appears to have been in '/home/user/demoplays.yaml': line 1, column 3, but may
  be elsewhere in the file depending on the exact syntax problem.
  
  The offending line appears to be:
  
  
  - name:"Do a demo"
    ^ here
  </code></pre>
  
  <p>At first I considered as yaml syntax error,however YAML linter   validated it was correct. I using  ansible 2.7.10 on my elementary OS Loki system. I am just started to learning Ansible and YAML and have not found any hint why that error happening!</p>