Redirect til fejlside

Jeg har et website, hvor jeg gerne vil smide folk over på en default side hver gang der opstår en fejl.

I min web config står der følgende:

<customErrors mode="RemoteOnly" defaultRedirect="Base/ErrorPage.aspx" />

Jeg får så følgende fejl:

Runtime Error
Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine.

Details: To enable the details of this specific error message to be viewable on remote machines, please create a <customErrors> tag within a "web.config" configuration file located in the root directory of the current web application. This <customErrors> tag should then have its "mode" attribute set to "Off".


<!-- Web.Config Configuration File -->

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


Notes: The current error page you are seeing can be replaced by a custom error page by modifying the "defaultRedirect" attribute of the application's <customErrors> configuration tag to point to a custom error page URL.


<!-- Web.Config Configuration File -->

<configuration>
    <system.web>
        <customErrors mode="RemoteOnly" defaultRedirect="mycustompage.htm"/>
    </system.web>
</configuration>

Smider jeg så min ErrorPage.aspx i roden af mit side og skriver:

<customErrors mode="RemoteOnly" defaultRedirect="ErrorPage.aspx" />

istedet, så virker det fint. Hvorfor får jeg ikke lov til at tilgå min fejlside, når den ligger i en undermappe?