Steps to Problem/Issue
- I installed Visual Studio 2012 RTM.
- Created an MVC 4 project template in Visual Studio 2012
- Without any code changes, I hit F5 debug.
- Issue: I get a pop up message “Unable to launch the IIS Express Web Serve“
After much searching and many suggest re-install Visual Studio 2012, but it takes a long time (>20 mins) and I’m pretty stubborn at times to find root cause.
I found myself looking at the applicationhost.config file located at
Look for <applicationPools> node.
I updated managedRuntimeVersion=”4.0″ to “4.0.30319”
<add name=”Clr4IntegratedAppPool” managedRuntimeVersion=”v4.0.30319″ managedPipelineMode=”Integrated” CLRConfigFile=”%IIS_USER_HOME%\config\aspnet.config” autoStart=”true” />
Back to Visual Studio 2012 Project Solution, I hit F5 Debug and IE loaded with the App!