How to Configure Detailed Error Pages for the FIM Portal - FIM 2010 R2

I am trying to configure detailed error pages for Fim Portal using this article:

How to Configure Detailed Error Pages for the FIM Portal

The problem is that I am using Fim 2010 R2 and I think that the article above is for Fim 2010.

There is (at least) one difference in web.config file. The article says "Enable the ILMError HTTP module" but in my web.config file there is not ILMEerror in httpModules section. Anyway ILMEerror is in modules section and I edited it as the article says.

Unfortunately now when I am connecting to the portal, I get this error message anytime:

Server Error in '/' Application.
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Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


[NullReferenceException: Object reference not set to an instance of an object.]
   Microsoft.IdentityManagement.WebUI.Controls.UICacheUtils.GetCacheKey(CacheKey key) +274
   Microsoft.IdentityManagement.WebUI.Controls.NavigationBarConfigurationModel.RetrieveSiteNodeFromCache() +118
   Microsoft.IdentityManagement.WebUI.Controls.NavigationBarProvider.BuildSiteMap() +63
   Microsoft.SharePoint.WebControls.AspMenu.AdjustForProviderMaximumDepth() +90
   Microsoft.SharePoint.WebControls.AspMenu.OnPreRender(EventArgs e) +49
   System.Web.UI.Control.PreRenderRecursiveInternal() +154
   System.Web.UI.Control.PreRenderRecursiveInternal() +239
   System.Web.UI.Control.PreRenderRecursiveInternal() +239
   System.Web.UI.Control.PreRenderRecursiveInternal() +239
   System.Web.UI.Control.PreRenderRecursiveInternal() +239
   System.Web.UI.Control.PreRenderRecursiveInternal() +239
   System.Web.UI.Control.PreRenderRecursiveInternal() +239
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +4105



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Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.33440 

So the case is I get that error message above straight after enabling detailed error pages. I think I shouldn't get that error mesage when the portal is working and now the error message is saying that my modifications broke something.

Any comments or ideas or something? Has the configuration changed for Fim 2010 R2?