Uncaught TypeError: Cannot set property 'textContent' of null code example

Example 1: Cannot read property 'setContent' of null

tinymce.init({
  selector:'textarea',
  init_instance_callback : function(editor) {
    editor.setContent('custom');
  }
});

Example 2: Uncaught TypeError: Cannot read property 'replace' of undefined

Add the class: "class="owl-carousel"

<div id="slider" class="owl-carousel owl-theme">