Cry about...
MS-Windows Troubleshooting

Server Too Busy


When trying to run a web application from within the Visual Studio 2012 (using the visual studio development server) the following is displayed in the browser window:

Server Too Busy

There are no other errors. Pressing F5 (to refresh the page) may work, and the error does not then reoccur until the site needs to be recompiled again.

The error is generated before any application startup code in global.asax is executed.

Possible Cause:

From my own experience this problem only happens on large projects and not small ones. Once it starts happening it happens more frequently.

So, I *think* this is likely to be related to the length of time it takes the just-in-time compiler to compile the site and get it up running.

Possible Remedies:

  • Press F5. Repeat until the site starts. Not very satisfactory but it is a simple work around.
  • Edit the web.config file and add delayNotificationTimeout with a sufficiently large value.

    Open the web.config file and find (or add) the tag httpRuntime. This tag should be inside <system.web> which in turn is inside <configuration>. Add (or amend) the setting for delayNotificationTimeout (you may need to add the httpRuntime line if it is not already present). The default is 5 seconds, I suggest doubling it and if the problem returns then double it again.

    So your web.config file will look something like:

        <httpRuntime delayNotificationTimeout="10" ... />

  • Whilst I have not tried this, I suspect that changing from using the Visual Studio Development Server to using the local IIS Web server might also avoid this problem.

These notes have been tested within Microsoft Visual Studio 2012 Professional, running under Windows 8 Professional and may apply to other versions as well.

About the author: is a dedicated software developer and webmaster. For his day job he develops websites and desktop applications as well as providing IT services. He moonlights as a technical author and consultant.