title: Why is ASP.NET throwing so many exceptions?
body: <p>By coincidence I watched the debug output of Visual Studio a bit. I can see hundreds and hundreds of various exceptions being thrown. I checked another ASP.NET based solution and it is showing same behavior. Why are all those exceptions thrown? I cannot believe it is good for the overall performance, is it?
  Look at the excerpt below. It is the output of appr. 30 seconds surfing. Most are HttpExceptions but there are also FormatExceptions and ArgumentOutOfRangeExceptions. None of these is really affecting the usage. Nothing crashes. Does anybody have an explanation, as it seems to be "normal"?</p>
  
  <pre><code>A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  'w3wp.exe' (Managed): Loaded 'C:\Windows\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\a402e511\e6aaa0de\App_Web_vdj_eurz.dll', Symbols loaded.
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.Web.HttpException' occurred in System.Web.dll
  A first chance exception of type 'System.InvalidCastException' occurred in mscorlib.dll
  A first chance exception of type 'System.InvalidCastException' occurred in mscorlib.dll
  A first chance exception of type 'System.ArgumentOutOfRangeException' occurred in mscorlib.dll
  A first chance exception of type 'System.ArgumentOutOfRangeException' occurred in mscorlib.dll
  A first chance exception of type 'System.FormatException' occurred in mscorlib.dll
  A first chance exception of type 'System.FormatException' occurred in mscorlib.dll
  </code></pre>