title: TinyMCE - An invalid form control with name='content' is not focusable
body: <p>I use TinyMCE 4 and this is my code for it:</p>
  
  <pre><code>&lt;script type="text/javascript" src="//cdn.tinymce.com/4/tinymce.min.js"&gt;&lt;/script&gt;
  &lt;script&gt;
         tinymce.init({
           selector: 'textarea[name=content]',
           plugins: 'image code',
           toolbar: 'undo redo | link image | code',
           image_title: true, 
           automatic_uploads: true,
           file_picker_types: 'image', 
           file_picker_callback: function(cb, value, meta) {
             var input = document.createElement('input');
             input.setAttribute('type', 'file');
             input.setAttribute('accept', 'image/*');
             input.onchange = function() {
               var file = this.files[0];
               var reader = new FileReader();
               reader.onload = function () {
               var id = 'blobid' + (new Date()).getTime();
               var blobCache =  tinymce.activeEditor.editorUpload.blobCache;
               var base64 = reader.result.split(',')[1];
               var blobInfo = blobCache.create(id, file, base64);
               blobCache.add(blobInfo);
               cb(blobInfo.blobUri(), { title: file.name });
             };
             reader.readAsDataURL(file);
           };
           input.click();
         }
       });  
  &lt;/script&gt;
  </code></pre>
  
  <p>and I have one problem. When I click on the "submit" button, the form isn' t send but in web browser console I have error: "An invalid form control with name='content' is not focusable." </p>
  
  <p>Please can you help me, how can I solve this problem simply? For all advice thanks in advance. </p>