Question

I control the code but not the server and the person at the other end knows as much about IIS as I do.

I have the classic:

<configuration>
    <system.web>
        <customErrors mode="Off"/>
    </system.web>
</configuration>

in my root level web.config, but am not seeing error details. Could the above have been overriden by a setting at the server/application level?

Answer 1

In the end the reason we weren’t seeing error messages was because the machine.config file of our dev server had <deployment retail="true"/> after being cloned from our production server:

<configuration>
    <system.web>
          <deployment retail="true"/>
    </system.web>
</configuration>

It needed to be set to false. Scott Guthrie elaborates on it in his post Don’t run production ASP.NET Applications with debug=”true” enabled.