Routing Error

[rasool-sb]

Hellow,
Am using ckeditor-rails for my app, I successfuly added the gem, installed, configured, and awesomely working, but when i click on browse button, the routing error displays on the screen, here am attaching the screenshot for reference,

and this is my optional configured config.js file details:-

CKEDITOR.editorConfig = function( config ) {
    config.filebrowserBrowseUrl = "/ckeditor/attachment_files";
    config.filebrowserImageBrowseLinkUrl = "/ckeditor/pictures";
    config.filebrowserImageBrowseUrl = "/ckeditor/pictures";
    config.filebrowserImageUploadUrl = "/ckeditor/pictures";
    config.filebrowserUploadUrl = "/ckeditor/attachment_files";  
    config.toolbar_basic = [
        [ 'Save', '-', 'Cut', 'Copy', 'Paste', 'PasteText', 'PasteFromWord',
        '-', 'Undo', 'Redo' ],
        [ 'Bold', 'Italic', 'Underline',
        '-','JustifyLeft','JustifyCenter','JustifyRight','JustifyBlock'],
        ['Smiley', 'Preview', 'Find', 'Replace', 'Link', 'Unlink', '-', 'Image' ],
        ['Table', 'Font', 'FontSize', '-', 'TextColor', 'BGColor', '-','Maximize']
    ];
    config.uiColor = "#eff4ff"
    config.toolbar = config.toolbar_basic;
};

My environment details: Ubuntu 12.04, ruby 1.9.3, rails 3.2.13.

Rake routes log:

   ckeditor_rails_engine        /ckeditor
   Ckeditor::Rails::Engine
   Routes for Ckeditor::Rails::Engine:

Please help me! many Thanks.. :)