Can't use WPF designer in VS2008 SP1

i searched several hours four solution and nothing found. If I open WPF Designer in my VS2008 Team Suite SP1 I become following error:

Loading this assembly would produce a different grant set from other instances. (Exception from HRESULT: 0x80131401) at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandle& ctor, Boolean& bNeedSecurityCheck) at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean fillCache) at System.RuntimeType.CreateInstanceImpl(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean fillCache) at System.Activator.CreateInstance(Type type, Boolean nonPublic) at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes) at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes) at System.Activator.CreateInstance(String assemblyName, String typeName, Boolean ignoreCase, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes, Evidence securityInfo, StackCrawlMark& stackMark) at System.Activator.CreateInstance(String assemblyName, String typeName) at System.AppDomain.CreateInstance(String assemblyName, String typeName) at System.AppDomain.CreateInstanceAndUnwrap(String assemblyName, String typeName) at System.AppDomain.CreateInstanceAndUnwrap(String assemblyName, String typeName) at MS.Internal.Package.VSIsolationProviderService.CreateIsolationProvider(String identity, AssemblyReferenceProvider assemblyReferences, IEnumerable`1 assemblyFolders) at MS.Internal.Providers.VSDesignerContext.GetIsolationProvider(IServiceProvider provider, IVsHierarchy hierarchy, AssemblyReferenceProvider assemblyReferences, Boolean isSilverlightProject) at MS.Internal.Providers.VSDesignerContext.GetIsolationProvider(IServiceProvider provider, IVsHierarchy hierarchy, AssemblyReferenceProvider assemblyReferences) at MS.Internal.Providers.VSDesignerContext.Initialize(IServiceProvider provider, IVsHierarchy hierarchy, UInt32 itemid, Object docDataObj)
at MS.Internal.Providers.VSDesignerContext..ctor(IServiceProvider provider, IVsWindowFrame frame, Object docDataObj) at MS.Internal.Providers.VSDesignerContext.GetContext(IServiceProvider services, IVsWindowFrame frame, Boolean createIfNotExist) at MS.Internal.Designer.DesignerPane.InitializeDesigner()

What I tried to this moment:

• Reset all settings in Visual Studio
• Closed any open XAML files in project, closed Visual Studio, re-opened VS, opened XAML file
• Create new user in operating system and try open solution with them
• Completed uninstallation/reinstallation of VS 2008 SP1 + MSDN, .NET 3.5 Framework SP1, Silverlight SDK, WPF Toolkit - January 2009

I run on Windows Vista SP1 32bit Business Edition.

Do any have a idea how can I solve it before I would try reinstalling operation system?

Regards Anton Kalcik

UPDATE: Also I tried to disable all add-ons.

First of all not only you receive this error so may be you should google it first? As you can see there are many behaviors of this problem and we are not able to figure out what is wrong in your case because it's hard to reproduce the problem. Also you may try to repair you VS or disable all your addins