ClickOnce Problem

I have a Visual Basic Application called Interest Calculator. I distribute it using Microsoft Clickonce. The program has worked well for many years. Recently after I made some changes to the program it now gives an error message when a user tries to install the program via the web? <[login to view URL]>: **Error Message **Cannot Continue. The application is improperly formatted. Contact the application vendor for assistance. whee I try to run the program within Visual Studio IDE i ge the following error message: Error? 2? Unable to emit assembly: Referenced assembly 'FocusedTextbox' does not have a strong name? Interest Calculator. I need someone to fix this error? so that users can download and install the program via clickonce.