I just flattened my machine and ran into this issue when running a Service Fabric hosted WebAPI project.
This line of code:
Was throwing this exception:
Luckily, I remembered that I ran into this same issue before and didn’t disable this when I rebuilt my machine. By default, Skype uses port 80 and 443. You, as a developer, should disable that. Uncheck this box under Tools—> Options –> Advanced –> Connection: “Use port 80 and 443 for additional incoming connections”.