Deploying website: 500 - Internal server error

Question

I am trying to deploy an ASP.NET application. I have deployed the site to IIS, but when visiting it with the browser, it shows me this:

Server Error

Answer 1

My first attempt to publish and then run a very simple site serving only HTML produced "The page cannot be displayed because an internal server error has occurred."

The problem: I had the site set to .NET 3.5 in Visual Studio (right click web site project -> Property Pages -> Build), but had the Web Site in Azure configured as .NET 4.0. Oops! I changed it to 3.5 in Azure, and it worked.