Converting Website to Web Application Causes Multiple "has multiple definitions with identical signatures." Errors.

Hi, we are converting our first website to a web application. We followed the tutorial. When we compile, we get hundreds of  "has multiple definitions with identical signatures." errors. I see lots of articles about this issue, but none about what to actually DO about the issue. Any help?

It's a VB project.

Error      20           'Protected Sub btnRunReport_Click(sender As Object, e As System.EventArgs)' has multiple definitions with identical signatures.

Error      21           'Protected Sub Page_Load(sender As Object, e As System.EventArgs)' has multiple definitions with identical signatures.