Compilation Error after publishing online

Mar 11, 2013 at 1:59 PM
Dear friends,
I am currently using EPPlus with my work. It works really well in Debug model(Reference is added).
However, when I released the project. I got a Compilation Error said
CS0246: The type or namespace name 'OfficeOpenXml' could not be found (are you missing a using directive or an assembly reference?)
Can anyone help me to figure this out.
Thanks
Chengzhi