rails 3 fckeditor xml request error

I am using rails 3 and Fckeditor gem and i am getting the following error can any one tell me why i am getting this error.

The server didn't send back a proper XML response. Please contact your system administrator.

XML request error: OK  (200)

Requested URL:
/fckeditor/command?Command=GetFoldersAndFiles&Type=Image&CurrentFolder=%2F&uuid=1409566296645

Response text:
    xml.instruct!
        #=> <?xml version="1.0" encoding="utf-8" ?>
    xml.Connector("command" => params[:Command], "resourceType" => 'File') do
        xml.CurrentFolder("url" => @fck_url, "path" => params[:CurrentFolder])
        xml.Folders do
            @folders.each do |folder|
                xml.Folder("name" => folder)
            end
        end if !@folders.nil?
        xml.Files do
            @files.keys.sort.each do |f|
                xml.File("name" => f, "size" => @files[f])
            end
        end if !@files.nil?
        xml.Error("number" => @errorNumber) if !@errorNumber.nil?
    end