What causes the VS 2010 SP1 WPF Designer to crash?

Question

We're experiencing crashes on various machines in the VS2010 WPF designer in the following scenario:

• VS 2010 SP1 installed
• 64 Bit Windows 7
• Reference to NHibernate.dll (Version 1.2.0.712)

To reproduce the Error, create a new WPF Solution, perform the following actions:

• create a new WPF solution
• open the main window, add a textbox to it, set some static text
• add a reference to FluentNhibernate.dll, Version 1.2.0.712
• Clean and Rebuild the solution
• Open main window in designer again, edit text
• in the designer, click left of the window, then back into the textbox again

There's no Data / Command Bindings, no code that references FluentNHibernate functionality or anything highly sophisticated, just a new WPF Solution with the following XAML in the MainWindow.xaml :

<Window x:Class="testWpfApplication2.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Width="800"
    Title="MainWindow" Height="350" >
  <Grid>
    <TextBox Text="yxcydfdssdfsdfdsfsdsddsasdyxcasd"  />
  </Grid>
</Window>

Here's the complete Stacktrace:

System.Reflection.TargetInvocationException
Exception has been thrown by the target of an invocation.
   at System.RuntimeMethodHandle._InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeType typeOwner)   
   at System.RuntimeMethodHandle.InvokeMethodFast(IRuntimeMethodInfo method, Object target, Object[] arguments, Signature sig, MethodAttributes methodAttributes, RuntimeType typeOwner)   
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)   
   at System.Delegate.DynamicInvokeImpl(Object[] args)   
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)   
   at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)

System.NullReferenceException
Object reference not set to an instance of an object.
   at Microsoft.VisualStudio.Shell.Design.VsTargetFrameworkUtil.GetRuntimeTypeVariable(Type type)   
   at Microsoft.VisualStudio.Shell.Design.VsTargetFrameworkUtil.GetRuntimeType(Type type)   
   at Microsoft.VisualStudio.Shell.Design.VsTargetFrameworkUtil.EnsureRuntimeType(Type type)   
   at Microsoft.VisualStudio.Shell.Design.VsTargetFrameworkUtil.GetRuntimeType(Type type)   
   at Microsoft.VisualStudio.Shell.Design.VsTargetFrameworkType.TryGetRuntimeType()   
   at Microsoft.VisualStudio.Shell.Design.VsTargetFrameworkUtil.EnsureRuntimeType(Type type)   
   at Microsoft.VisualStudio.Shell.Design.VsTargetFrameworkProvider.GetRuntimeType(Type reflectionType)   
   at MS.Internal.Package.VSIsolationProviderService.RemoteReferenceProxy.VsReflectionResolver.GetRuntimeType(Type reflectionType)   
   at Microsoft.Windows.Design.Metadata.ReflectionMetadataContext.CachingReflectionResolver.GetRuntimeType(Type reflectionType)   
   at Microsoft.Windows.Design.Metadata.ReflectionMetadataContext.Microsoft.Windows.Design.Metadata.IReflectionResolver.GetRuntimeType(Type reflectionType)   
   at MS.Internal.Metadata.ClrType.get_RuntimeMember()   
   at MS.Internal.Metadata.ClrMember`1.Microsoft.Windows.Design.Metadata.Reflection.IReflectionMember.get_MemberInfo()   
   at MS.Internal.Metadata.ClrType.Equals(Object obj)   at System.Collections.Generic.ObjectEqualityComparer`1.Equals(T x, T y)   
   at System.Collections.Generic.Dictionary`2.FindEntry(TKey key)   
   at Microsoft.Windows.Design.Metadata.Xaml.XamlExtensionImplementations.<>c__DisplayClass5.<FindAttachableProperties>b__4(ITypeMetadata walkType)   
   at MS.Internal.Design.Metadata.Xaml.XamlType.<GetAllAttachableProperties>d__7.MoveNext()   
   at MS.Internal.Design.Metadata.Xaml.XamlType.<FindAttachableProperties>d__0.MoveNext()   
   at Microsoft.Windows.Design.Metadata.Xaml.XamlExtensionImplementations.<FindAttachableProperties>d__7.MoveNext()   
   at MS.Internal.VirtualModel.VirtualModelPropertyCollection.<GetUncachedProperties>d__0.MoveNext()   
   at System.Linq.Buffer`1..ctor(IEnumerable`1 source)   
   at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)   
   at MS.Internal.VirtualModel.VirtualModelPropertyCollection.GetEnumerator()  
   at MS.Internal.Designer.PropertyEditing.Model.Properties.ModelPropertyMerger.<GetFirstProperties>d__0.MoveNext()   
   at MS.Internal.Designer.PropertyEditing.Views.PropertyEntryReader.RedraftEntries(IPropertyViewManager viewManager, Selection selection, Boolean attachedOnly, IEventCodeBehindProxy eventCodeBehindProxy, CategoryList categoryList)   
   at MS.Internal.Designer.PropertyEditing.PropertyInspector.UpdateCategories(Selection selection, Boolean attachedOnly, IEntryReader entryReader)   
   at MS.Internal.Designer.PropertyEditing.PropertyInspector.RefreshPropertyList(Boolean attachedOnly)   
   at MS.Internal.Designer.PropertyEditing.PropertyInspector.OnSelectionChangedIdle()

MS has confirmed this as a SP1 Bug, but for a satisfactory outcome, I need to understand more about the issue...

What causes this, why does it occur only when addind FNH, why only when adding it from a certain location (assembly is the same - we did a bytewise comparison)? Without SP1, it works...

Answer 1

We sometimes get around this by adding

if (System.ComponentModel.DesignerProperties.GetIsInDesignMode(this))
                return;

in the loaded event of the offending control