Hi Everyone,I have created the excel project with Ribbon & UDF in c#. It works perfect when I build the solution or debug from VS 2010. Now I need to create a installer for this project. I have created a installer using setup wizard in VS 2010. When I open Excel, the ribbon loaded successfully, but Formula not found in automation list. I have searched so many blogs but didn't get any solution. You can find project ref. here- C# Ramblings: Communicating Between VSTO and UDF's in Excel Any help will be appreciated!!!