TF400898: An Internal Error Occured.

Server side exceptions:

System.ArgumentOutOfRangeException: startIndex cannot be larger than length of string.

Parameter name: startIndex

   at System.String.InternalSubStringWithChecks(Int32 startIndex, Int32 length, Boolean fAlwaysCopy)

   at Microsoft.TeamFoundation.Server.WebAccess.Routing.TfsRoute.GetRouteData(HttpContextBase httpContext)

   at System.Web.Routing.RouteCollection.GetRouteData(HttpContextBase httpContext)

   at System.Web.Routing.UrlRoutingModule.PostResolveRequestCache(HttpContextBase context)

   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Explanation:

This error occurred while trying to access the TFS 2012 update 3 server team project website for viewing boards or creating PBIs, bugs and other work items. The error can be reproduced by clicking back and forth a few times between the home page and CODE, WORK, TEST, etc. The issue was specific to one specific collection in the server. 

Fix:

One of the team project's shared query with wrong condition clause was trying to load 73000+ WIs which was pinned to the Team Favorites in the home page causing the issue. The issue was resolved after correcting the query.