title: On Redux-Form Validations disappear because the actions UNREGISTERED_FIELD/REGISTER_FIELD are triggered (twice)
body: <p>I am using React 16, Redux-form 7
  I have a field with a validation. When I change the value the UPDATE_SYNC_ERRORS is triggered and syncErrors correctly added to the state. Then automatically two series of UNREGISTERED_FIELD/REGISTER_FIELD are triggered and the syncErrors are eliminated and never recreated, even though the value of the field is still incorrect. </p>
  
  <pre><code>&lt;Field
      name="afield"
      validate={[ required, number, minValue(100) ]}
      component={props =&gt; &lt;AnInput options={options} {...props} /&gt;}
    /&gt;
  
      const AnInput = props =&gt; {
    const {
      options: { label, prompt, helpText },
      input,
      meta: { touched, dirty, error, warning }
    } = props;
  
    return (
      &lt;div className="form-group"&gt;
        &lt;label&gt;
          {label}
        &lt;/label&gt;
        &lt;div &gt;
          &lt;input
            {...input}
          /&gt;
          {touched &amp;&amp;
            ((error &amp;&amp; &lt;span&gt;{error}&lt;/span&gt;) ||
              (warning &amp;&amp; &lt;span&gt;{warning}&lt;/span&gt;))}
        &lt;/div&gt;
        {helpText &amp;&amp; &lt;FieldHelp title={label} helpText={helpText} /&gt;}
      &lt;/div&gt;
    );
  };
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/sLeLf.png" rel="nofollow noreferrer">Actions triggered when field is changed</a></p>