Add known issue for RC1 incompatibility with 17.11 (#9489)

Author: marcpopMSFT

release-notes/9.0/known-issues.md

@@ -4,26 +4,27 @@ You may encounter the following known issues, which may include workarounds, mit
 
 ## .NET WPF
 
-#### 1. Usage of incorrect types as DynamicResource
-In earlier previews (or .NET 8 and before), applications that attempted to use a `DynamicResource` with incorrect types, and referenced the same from a library, would silently fail by swallowing the exception. However, with the introduction of DynamicResource optimization [here](https://github.com/dotnet/wpf/pull/5610), this behavior has changed. The same implementation will now result in a `XamlParseException` being thrown, potentially causing the application to crash.
+### 1. Usage of incorrect types as DynamicResource
+In earlier previews (or .NET 8 and before), applications that attempted to use a `DynamicResource` with incorrect types, and referenced the same from a library, would silently fail by swallowing the exception. However, with the introduction of DynamicResource optimization [here](https://github.com/dotnet/wpf/pull/5610), this behavior has changed.
+The same implementation will now result in a `XamlParseException` being thrown, potentially causing the application to crash.
 
 The crash might look something like this:
-```
+```cs
 PresentationFramework.dll!System.Windows.Markup.XamlReader.RewrapException(System.Exception e, System.Xaml.IXamlLineInfo lineInfo, System.Uri baseUri)
 PresentationFramework.dll!System.Windows.Markup.WpfXamlLoader.Load(System.Xaml.XamlReader xamlReader, System.Xaml.IXamlObjectWriterFactory writerFactory, bool skipJournaledProperties, object rootObject, System.Xaml.XamlObjectWriterSettings settings, System.Uri baseUri)
 PresentationFramework.dll!System.Windows.Markup.WpfXamlLoader.LoadBaml(System.Xaml.XamlReader xamlReader, bool skipJournaledProperties, object rootObject, System.Xaml.Permissions.XamlAccessLevel accessLevel, System.Uri baseUri)
 PresentationFramework.dll!System.Windows.Markup.XamlReader.LoadBaml(System.IO.Stream stream, System.Windows.Markup.ParserContext parserContext, object parent, bool closeStream)
 PresentationFramework.dll!System.Windows.Application.LoadComponent(object component, System.Uri resourceLocator)
 ```
 
-#### Mitigation:
+### Mitigation
 Developers can prevent this crash by updating the resource with the correct value types. However, for those who need to maintain the previous behavior, an **opt-out switch** is being provided in the .NET 9 RC1 release. This switch allows applications to revert to the unoptimized `DynamicResource` usage.
 
 
-#### 2. Incorrect rendering of applications launched with dark theme
+### 2. Incorrect rendering of applications launched with dark theme
 Applications using library-based themes might encounter incorrect rendering of the dark theme due to the implementation of the `Fluent` theme. This could result in incorrect resource settings for windows, such as background and accent colors, which may appear transparent.
 
-#### Available Workaround:
+### Available Workaround
 This issue occurs only when starting the application with the dark theme enabled. To ensure correct rendering, the resources can be reloaded. This reloading process can be implemented by hooking into a window event, such as `ContentRendered`.
 
 The implementation for the same would look something like this -
@@ -39,3 +40,15 @@ private void ReactiveWindow_ContentRendered(object sender, System.EventArgs e)
 ```
 
 The behavior will be **fixed in .NET 9 RC1** release.
+
+## .NET SDK
+
+### .NET 9.0.100-RC.1 will fail when used with 17.11
+
+There is an incompatible dependency between a file loaded from the SDK and the dependencies that Visual Studio includes.
+
+`
+NETSDK1060 Error reading assets file: Error loading lock file '...\obj\project.assets.json' : Could not load file or assembly 'System.Text.Json, Version=8.0.0.4, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies. The system cannot find the file specified.
+`
+
+This behavior will be **fixed in an upcoming Visual Studio 17.11.x** release