Responsive filemanager in tinymce and CodeIgniter: Getting a 404 error

Did you read the Documentation on their Web site?

You need to add js code for editors etc;

Code:

<script src="<?php echo base_url('assets/admin/vendor/tinymce/tinymce.min.js'); ?>"></script>
<script>tinymce.init({
   selector: 'textarea',
 height: 500,
 theme: 'modern',
 plugins: 'searchreplace autolink directionality visualblocks visualchars image link media codesample table charmap hr nonbreaking anchor toc insertdatetime advlist lists textcolor wordcount code imagetools contextmenu colorpicker textpattern help responsivefilemanager ',
 toolbar1: 'formatselect | bold italic strikethrough forecolor backcolor | link | image responsivefilemanager |  code | alignleft aligncenter alignright alignjustify  | numlist bullist outdent indent blockquote | removeformat | ',
 image_advtab: true,
       relative_urls: false,
       remove_script_host: false,

       external_filemanager_path:"<?php echo base_url(); ; ?>filemanager/",
       filemanager_title:"Responsive Filemanager" ,
       external_plugins: { "filemanager" : "<?php echo base_url(); ; ?>filemanager/plugin.min.js"},

        branding: false,
         elementpath: false,
        skin: "lightgray",
        convert_fonts_to_spans : true,
        custom_undo_redo_levels: 1000,
        invalid_elements : 'html,body,head,script',

          menu: {
   edit: {title: 'Edit', items: 'undo redo | cut copy paste pastetext | selectall'},
   insert: {title: 'Insert', items: 'link responsivefilemanager media | template hr'},
   view: {title: 'View', items: 'visualaid | code'},
   format: {title: 'Format', items: 'bold italic underline strikethrough superscript subscript | formats | removeformat'},
   table: {title: 'Table', items: 'inserttable tableprops deletetable | cell row column'}
 }
});

Yep i followed their guide on how to install it.

update/edit:
when i inspect the button on the wysiwyg editor its shows me a 404 for the dialog.php window, event though that the file exist. thats why i think that its something with my routing that is messed up.