Got this error....
How to fix it? Site is not usable!!!!
Server Error in '/' Application.
--------------------------------------------------------------------------------
An item with the same key has already been added.
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.ArgumentException: An item with the same key has already been added.
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:
[ArgumentException: An item with the same key has already been added.]
System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) +51
System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +7462172
System.Collections.ObjectModel.KeyedCollection`2.AddKey(TKey key, TItem item) +93
System.Collections.ObjectModel.KeyedCollection`2.InsertItem(Int32 index, TItem item) +38
System.Collections.ObjectModel.Collection`1.Add(T item) +117
DotNetNuke.ComponentModel.SimpleContainer.RegisterComponentInstance(String name, Type contractType, Object instance) +135
DotNetNuke.ComponentModel.AbstractContainer.RegisterComponentInstance(Object instance) +82
DotNetNuke.ComponentModel.ComponentFactory.RegisterComponentInstance(Object instance) +77
DotNetNuke.Security.Membership.AspNetMembershipProvider..ctor() +189
[TargetInvocationException: Exception has been thrown by the target of an invocation.]
System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandle& ctor, Boolean& bNeedSecurityCheck) +0
System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean fillCache) +86
System.RuntimeType.CreateInstanceImpl(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean fillCache) +230
System.Activator.CreateInstance(Type type, Boolean nonPublic) +67
System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes) +1051
System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes) +111
System.RuntimeType.InvokeMember(String name, BindingFlags bindingFlags, Binder binder, Object target, Object[] providedArgs, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParams) +7648755
System.Type.InvokeMember(String name, BindingFlags invokeAttr, Binder binder, Object target, Object[] args, CultureInfo culture) +36
DotNetNuke.Framework.Reflection.CreateInstance(Type Type) +27
DotNetNuke.ComponentModel.SingletonComponentBuilder.CreateInstance() +14
DotNetNuke.ComponentModel.SingletonComponentBuilder.BuildComponent() +16
DotNetNuke.ComponentModel.SimpleContainer.GetComponent(IComponentBuilder builder) +18
DotNetNuke.ComponentModel.SimpleContainer.GetComponent(Type contractType) +81
DotNetNuke.ComponentModel.AbstractContainer.GetComponent() +55
DotNetNuke.ComponentModel.ComponentFactory.GetComponent() +63
DotNetNuke.Security.Membership.MembershipProvider.Instance() +9
DotNetNuke.Entities.Users.UserController..cctor() +5
[TypeInitializationException: The type initializer for 'DotNetNuke.Entities.Users.UserController' threw an exception.]
DotNetNuke.Entities.Users.UserController.GetCurrentUserInfo() +0
DotNetNuke.Services.Exceptions.BasePortalException.InitializePrivateVariables() +278
--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:2.0.50727.3082; ASP.NET Version:2.0.50727.3082