IIS Express – The specified port is in use
Somewhere between using webdeploy to send files to a dev server a few times yesterday I started getting this message locally. Googling for it turns up lots of results of how to change your port etc.
The root cause of this message in my case was that Entity Framework was looking for a connection string that didn’t exist in my config files. I’d renamed it to match another that we use for the same database in a different application that is deployed in the machine.config file on our servers. Creating a DB Context in the constructor for the default controller caused IIS Express to toss this message and fail to load pages.