Tuesday, October 27, 2009

Internal Error 500 returned by IIS7 hosted WCF services

500 Here's an issue I had for quite a long time.
For some (unknown at the time) reason the server was returning a "500 - Internal Server error" whenever an exception was thrown.
Even the message on the exception was an html document (pasted below), so who was modifying my exceptions? it turned out to be the IIS itself due to some configuration settings.
There's a "feature" which avoids the IIS to send the real exception to the client sending instead a more "friendly" one.
So, how do you change that? (keep in mind this is IIS 7.0 and above)
Take a look at this great post (where I got the solution from) and follow step 2) of "Enable IIS7 detailed errors".

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<
html xmlns="http://www.w3.org/1999/xhtml">
<
head>
<
meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"/>
<
title>500 - Internal server error.</title>
<
style type="text/css">
<!--
body
{margin:0;font-size:.7em;font-family:Verdana, Arial, Helvetica, sans-serif;background:#EEEEEE;}
fieldset{padding:0 15px 10px 15px;}
h1{font-size:2.4em;margin:0;color:#FFF;}
h2{font-size:1.7em;margin:0;color:#CC0000;}
h3{font-size:1.2em;margin:10px 0 0 0;color:#000000;}
#header{width:96%;margin:0 0 0 0;padding:6px 2% 6px 2%;font-family:"trebuchet MS", Verdana, sans-serif;color:#FFF;
background-color:#555555;}
#content{margin:0 0 0 2%;position:relative;}
.content-container{background:#FFF;width:96%;margin-top:8px;padding:10px;position:relative;}
-->
</style>
</
head>
<
body>
<
div id="header"><h1>Server Error</h1></div>
<
div id="content">
<
div class="content-container"><fieldset>
<
h2>500 - Internal server error.</h2>
<
h3>There is a problem with the resource you are looking for, and it cannot be displayed.</h3>
</
fieldset></div>
</
div>
</
body>
</
html>

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