Error renaming ASP.NET MVC project

Question

I have copied a previous project and renamed it. Once I had successfully renamed all the name spaces and it build correctly. I got the following error when I ran the application

Answer 1

This problem will occur if you have two assemblies in the same bin folder which contain an OwinStartup class. Normally you should not have two OwinStartup classes for the same web application.

You can solve this by inspecting your bin folder. If after the rename an assembly with the old name has remained in the bin folder you will get this error. To solve it delete everything from the bin folder.