I have site where a few of the back-end users must only be able to access a custom section. It seems however that as soon as none of the standard Umbraco sections are accessible by the logged in user, the error below occurs. It causes the list of available apps (content, media, developer, [custom-section] etc.) to disappear entirely.

Is there any way to work around this, or must I assign rights to at least one standard section for a user to be valid?

Message:

The current user doesn't have access to this application. Please contact the system administrator.

Stack:

System.Web.HttpUnhandledException: Exception of type 'System.Web.HttpUnhandledException' was thrown. ---> System.ArgumentException: The current user doesn't have access to this application. Please contact the system administrator.
   at umbraco.cms.presentation.TreeInit.Page_Load(Object sender, EventArgs e)
   at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)
   at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)
   at System.Web.UI.Control.OnLoad(EventArgs e)
   at umbraco.BasePages.BasePage.OnLoad(EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   --- End of inner exception stack trace ---
   at System.Web.UI.Page.HandleError(Exception e)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest()
   at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)
   at System.Web.UI.Page.ProcessRequest(HttpContext context)
   at ASP.umbraco_treeinit_aspx.ProcessRequest(HttpContext context) in c:\Windows\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\root\6ec8c91c\e0dd8a56\App_Web_treeinit.aspx.5f2dec3.mtsw1yek.0.cs:line 0
   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Umbraco v4.0.3