Can you please explain a bit?
What OS do you have?
What do you mean by "activate errors"?
Probably, you see custom error page when accessing domain, and cannot see real error from ASP.NET, right?
Have you tried to enable detailed errors in your web.config file directly?
I'm talking about these sections:
Code:
<system.web>
<customErrors mode="Off"/>
</system.web>
<system.webServer>
<httpErrors errorMode="Detailed" />
</system.webServer>