Hi,I have installed Visual Studio 2013 in my system. Due to some problems, I got the release after few months. So I was excited to use it and taste its new features. One thing I like about Visual Studio 2013 is it has a theme which turns it like Visual Studio 2010, which was simply awesome.

HTTP Error 500.23

I opened a existing website and tried to run that website. The website was using ASP.NET framework 4.0. However, the website has no errors and working fine in previous version of Visual Studio. But when I started with debugging (F5), this produced following error.

Solution

I can not understand the problem in a single view, as it suggest to change some configuration different methods in things you can try section. While there is not handler configured in web.config system for Web Server. Instead there was no system.webServer node.
So I searched in Internet and found some suggestion to make changes in Application Pool setting in IIS Manager. I tried that too but that was also a failed trial. Then suddenly I got a click in my mind and tried a setting which worked immediately.
How can the change done in Internet Information Service (IIS) Manager reflect in Development server. When we run the website from Visual Studio it loads in development server instead of IIS. So we have to make change in Development server which will automatically solve all the problems.
I thought, some time you might have same situation and solution must be there before problem.
Step 1: Open visual studio and click in the name of Website Project currently opened. Click on Property pane

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Step 2: Double click on Managed Pipeline Mode. This will toggle between Classic and Integrated Mode. You have to switch to Classic mode because the error was “An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode”

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Now hit the F5 button, here goes output as usual.

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+Prithvi Raj Bhatt