Detailed 500 error message, ASP + IIS 7.5

I have come to the same problem and fixed the same way as Alex K.

So if "Send Errors To Browser" is not working set also this:

Error Pages -> 500 -> Edit Feature Settings -> "Detailed Errors"

Also note that if the content of the error page sent back is quite short and you're using IE, IE will happily ignore the useful content sent back by the server and show you its own generic error page instead. You can turn this off in IE's options, or use a different browser.

Double click "ASP" in the site's Home screen in IIS admin, expand "Debugging Properties", enable "Send errors to browser", and click "Apply".

Under "Error Pages" on the home screen select "500", then "Edit feature settings" and select "Detailed Errors".

Note that the same steps apply for IIS 8.0 (Windows Server 2012).

If you're on a remote server you can configure your web.config file like so:

<configuration>
<system.webServer>
    <httpErrors errorMode="Detailed" />
    <asp scriptErrorSentToBrowser="true"/>
</system.webServer>
<system.web>
    <customErrors mode="Off"/>
    <compilation debug="true"/>
</system.web>