This site can’t be reached [site]'s server DNS address could not be found. ERR_NAME_NOT_RESOLVED

I'm running windows 10 and IIS version 1511(build 10586.164) I have the default app pools running and the the default html displayed. All of the other sites I've added give the same

This site can’t be reached [site]'s server DNS address could not be found. ERR_NAME_NOT_RESOLVED

I have used both visual studio 2012 and VS community 15. The MVC 4 version of my project site had been running fine.

I am rebuilding in asp.net 4.61 MVC 5, to avoid the regular clashes with version types and stopping nuget updating me into a problem.

Using the default template for 4.61 MVC 5 I have an app that VS 15 can run.

The old site gives the following error and displays the favicon when run through VS and IIS.

Could not load file or assembly 'System.Web.Razor, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) error, so I'm parking it rather than getting archaeological.

Currently the sites are bound to a host name and port number, * IP Address.

I have checked SO questions:

IIS 10 500.19 error and How to run ASP.NET MVC app in IIS 10 on Windows 10

among others.

Any ideas? It feels like it's something simple but I can't see it for trying.

Try running ipconfig /flushdns from the command line, worked for me!