System.Windows.Markup.XamlParseException provides no file name

_This issue has been moved from [a ticket on Developer Community](https://developercommunity2.visualstudio.com/t/SystemWindowsMarkupXamlParseException/1049255)._

---
It is very difficult to locate the root of an "System.Windows.Markup.XamlParseException" at rumtime. The position in the file is in the exception message but the file name ist missing. This is even more difficult if the problem is located in one of the merged dictionaries. Then the Exception doesn't pop up in the constructor of the control but as "Application is in a break mode" with no useful call stack at all.

**Exception details:**
System.Windows.Markup.XamlParseException
HResult=0x80131501
Message=**Zeilennummer "11" und Zeilenposition "5"** von "Durch Hinzufügen eines Werts zu einer Sammlung vom Typ "System.Windows.Controls.UIElementCollection" wurde eine Ausnahme ausgelöst.".
Source=PresentationFramework
StackTrace:
at System.Windows.FrameworkTemplate.LoadTemplateXaml(XamlReader templateReader, XamlObjectWriter currentWriter)
at System.Windows.FrameworkTemplate.LoadTemplateXaml(XamlObjectWriter objectWriter)
at System.Windows.FrameworkTemplate.LoadOptimizedTemplateContent(DependencyObject container, IComponentConnector componentConnector, IStyleConnector styleConnector, List`1 affectedChildren, UncommonField`1 templatedNonFeChildrenField)
at System.Windows.FrameworkTemplate.LoadContent(DependencyObject container, List`1 affectedChildren)
at System.Windows.StyleHelper.ApplyTemplateContent(UncommonField`1 dataField, DependencyObject container, FrameworkElementFactory templateRoot, Int32 lastChildIndex, HybridDictionary childIndexFromChildID, FrameworkTemplate frameworkTemplate)
at System.Windows.FrameworkTemplate.ApplyTemplateContent(UncommonField`1 templateDataField, FrameworkElement container)
at System.Windows.FrameworkElement.ApplyTemplate()
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Grid.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
at System.Windows.Controls.ContentPresenter.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Border.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.Controls.Control.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at MS.Internal.Helper.MeasureElementWithSingleChild(UIElement element, Size constraint)
at System.Windows.Controls.ContentPresenter.MeasureOverride(Size constraint)
at System.Windows.FrameworkElement.MeasureCore(Size availableSize)
at System.Windows.UIElement.Measure(Size availableSize)
at System.Windows.ContextLayoutManager.UpdateLayout()
at System.Windows.UIElement.UpdateLayout()
at System.Windows.Interop.HwndSource.SetLayoutSize()
at System.Windows.Interop.HwndSource.set_RootVisualInternal(Visual value)
at System.Windows.Interop.HwndSource.set_RootVisual(Visual value)
at System.Windows.Window.SetRootVisual()
at System.Windows.Window.SetRootVisualAndUpdateSTC()
at System.Windows.Window.SetupInitialState(Double requestedTop, Double requestedLeft, Double requestedWidth, Double requestedHeight)
at System.Windows.Window.CreateSourceWindow(Boolean duringShow)
at System.Windows.Window.CreateSourceWindowDuringShow()
at System.Windows.Window.SafeCreateWindowDuringShow()
at System.Windows.Window.ShowHelper(Object booleanBox)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.DispatcherOperation.InvokeImpl()
at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
at MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(Object obj)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at MS.Internal.CulturePreservingExecutionContext.Run(CulturePreservingExecutionContext executionContext, ContextCallback callback, Object state)
at System.Windows.Threading.DispatcherOperation.Invoke()
at System.Windows.Threading.Dispatcher.ProcessQueue()
at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
at System.Windows.Application.RunDispatcher(Object ignore)
at System.Windows.Application.RunInternal(Window window)
at System.Windows.Application.Run(Window window)
at System.Windows.Application.Run()
at MvvmApplication6.App.Main()

This exception was originally thrown at this call stack:
[External Code]

Inner Exception 1:
ArgumentException: Instanz vom Typ "String" kann keiner Sammlung vom Typ "UIElementCollection" hinzugefügt werden. Es sind nur Objekte vom Typ "UIElement" zulässig.

---
### Original Comments

#### Feedback Bot on 5/26/2020, 03:33 PM:

(private comment, text removed)
#### Feedback Bot on 7/3/2020, 11:45 AM:

(private comment, text removed)
#### Fiona Niu [MSFT] on 1/21/2022, 01:06 PM:

(private comment, text removed)
#### Desiree.Nissel on 1/21/2022, 01:54 PM:

(private comment, text removed)
#### Feedback Bot on 2/7/2022, 03:08 PM:

(private comment, text removed)

---
### Original Solutions
(no solutions)