After migrating our SingalR based project from Visual Studio 2010 to Visual Studio 2012 we got this error while running our solution:
This operation requires IIS integrated pipeline mode.
A simple fix is to edit your web project settings to use local IIS server as follows:
The reason being that SignalR requires integrated mode so you need to modify the project to use IIS Express instead of the default Cassini web server. Note that IIS should be installed in your system before making this change.