Detailed 500 error message, ASP + IIS 7.5

Question

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.

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>

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).

After trying Vaclav's and Alex's answer, I still had to disable "Show friendly HTTP error messages" in IE

In web.config under

<system.webServer>

replace (or add) the line

<httpErrors errorMode="Detailed"></httpErrors>

with

<httpErrors existingResponse="PassThrough" errorMode="Detailed"></httpErrors>

This is because by default IIS7 intercepts HTTP status codes such as 4xx and 5xx generated by applications further up the pipeline.

Next, enable "Send Errors to Browser" under the "ASP" section, and under "Error Pages / Edit Feature Settings", select "Detailed errors".

Also, give Write permissions on the website folder to the IIS_IUSRS builtin group.