TinyMCE doesn't work on FireFox
This can happen if TinyMCE cannot determine the correct suffix for its plugin / theme files. Usually this happens when you rename the TinyMCE main script file. Note that the TinyMCE script loader has a hard-coded list of recognized file names:
// Script types supported:// tinymce.js tinymce.min.js tinymce.dev.js// tinymce.jquery.js tinymce.jquery.min.js tinymce.jquery.dev.js// tinymce.full.js tinymce.full.min.js tinymce.full.dev.jsso you might need to provide the default ".min" suffix programmatically if you really need to have a non-standard file name for the main TinyMCE script file:
tinymce.suffix = ".min"
Please try this code it will work 100%
<!DOCTYPE html><html><head> <title></title></head><script src="//tinymce.cachefly.net/4.1/tinymce.min.js"></script> <script type="text/javascript"> tinymce.init({ selector: "textarea", theme: "modern", font_size_classes : "fontSize1, fontSize2, fontSize3, fontSize4, fontSize5, fontSize6", plugins: [ "advlist autolink link image lists charmap print preview hr anchor pagebreak spellchecker", "searchreplace wordcount visualblocks visualchars code fullscreen insertdatetime media nonbreaking", "save table contextmenu directionality emoticons template paste textcolor" ], toolbar: "insertfile undo redo | styleselect | bold italic | alignleft aligncenter alignright alignjustify | bullist numlist outdent indent | link image | print preview media fullpage | forecolor backcolor emoticons | sizeselect | fontselect | fontsize | fontsizeselect", style_formats: [ {title: 'Bold text', inline: 'b'}, {title: 'Red text', inline: 'span', styles: {color: '#ff0000'}}, {title: 'Red header', block: 'h1', styles: {color: '#ff0000'}}, {title: 'Example 1', inline: 'span', classes: 'example1'}, {title: 'Example 2', inline: 'span', classes: 'example2'}, {title: 'Table styles'}, {title: 'Table row 1', selector: 'tr', classes: 'tablerow1'} ] });</script><body><textarea name="text_box"></textarea></body></html>
embed the js inside the php.
or
you should find relative path to your js folder(not using base_url)