The page cannot be displayed because an internal server error has occurred.

IIS 6

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

IIS 7

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

IIS 8

<system.web>
   <customErrors mode="Off" />
</system.web>
<system.webServer>
   <httpErrors existingResponse="PassThrough" errorMode="Detailed"/>
</system.webServer>

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