title: Getting the error " TypeError: Cannot create property 'validator' on string 'control'"
body: <p>I am getting the error:
  TypeError: Cannot create property 'validator' on string 'control'"</p>
  
  <pre><code>import { Component, ChangeDetectionStrategy, OnInit } from '@angular/core';
  import { CommonModule } from '@angular/common';
  import { BrowserModule } from '@angular/platform-browser';
  import { DataStorageService, FieldConfig, ImportType } from '../../../../services/datastorage.service';
  import { ReactiveFormsModule, FormGroup, FormArray, FormControl } from '@angular/forms';
  
  
  import * as Papa from 'papaparse';
  @Component({
    selector: 'field-analysis',
    templateUrl: './field-analysis.component.html'
  })
  
  export class FieldAnalysisComponent implements OnInit {
  
    fieldsGroup;
  
    ngOnInit() {
      this.fieldsGroup = new FormGroup({ fieldset: new FormArray([new FormControl(''), new FormControl('')]) });
  
    }
  
  }
  </code></pre>
  
  <p>And the template looks like this.</p>
  
  <pre><code>&lt;h2 &gt;Field Definition&lt;/h2&gt;
  &lt;form formGroup="fieldsGroup" novalidate&gt;
  
  
  &lt;input *ngFor="let control of fieldsGroup.controls['fieldset'].controls" formControl="control"&gt;
  &lt;/form&gt;
  </code></pre>