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
I did not rename my solution, but I did run into this problem. I couldnt find a solution posted anywhere about this. I had 2 separate projects with an owin startup class on the same server. I simply gave each one a different "Friendly Name" as suggested in the exception message, and it solved it. I found a good article on this:
Owin Startup Class
To rename it, all you need to do is add a string on the OwinStartup Like so:
[assembly: OwinStartup("ProductionConfiguration", typeof(StartupDemo.ProductionStartup2))]