This GitHub issue is a meta issue that tracks opened issues in the Microsoft community system that relate to the developer experience of maintainers and contributors.

If you are building an application with Uno then you typically won't run into these sorts of issues. If you do experience any issues building an application with Uno, we want to know about it. Please open an issue and select either the bug report or the feedback template.

Note for maintainers, this list is maintained by issue priority. VS Preview issues should be added last.

Blocking issues for Visual Studio Windows

1. net8.0 must be first for WebAssembly publishing/debugging to work
   
2. Visual Studio launches browser without a valid URL and then fails to attach
3. Visual Studio starts Android Emulator when debugging an multi-project solution from Uno template
   

Issues for Visual Studio Windows

1. https://developercommunity.visualstudio.com/t/WebAssembly-app-freezes-when-debugger-is/10980946
2. Selecting an Android/iOS Simulator while active TFM is net10.0-browserwasm does not change the active target framework to ios/android for Uno project
3. When performing hot-reload some MetadataUpdateHandler are delayed
4. [HR] Exception while emitting update: System.NullReferenceException dotnet/maui#27612
5. Hot Reload performance and reliability
6. https://developercommunity.visualstudio.com/t/Visual-Studio-launches-browser-without-a/10957495
7. ItemGroups are created regardless of globbed definition when adding new controls (Uno When adding a new page via copy-paste, the csproj adds ItemGroups that makes the new page uncompilable #16605)
8. Building a cross-targeted project with many targets builds all targets even if only one is used
9. Add new item wizard does not have Apple items
10. Very slow IntelliSense on relatively small code base dotnet/roslyn#67926
11. https://developercommunity.visualstudio.com/t/vsconfig-extension-always-displayed-as/10823565
12. ArgumentNullException while executing a post for topic on iOS remote Mac build
13. Project properties don't open
14. https://developercommunity.visualstudio.com/t/Used-private-members-are-showing-up-as-u/10896472
15. MCP server list is inconsistent on Visual Studio startup https://github.com/unoplatform/private/issues/1061

Blocking Issues for .NET Mobile

1. New error in .NET 8 Android projects dotnet/runtime#123972
2. https://github.com/xamarin/xamarin-macios/issues/22102
3. [AOT] Failure when the path to the temp folder contains accentuated characters and/or spaces dotnet/android#9523

.NET Mobile Issues

1. iOS app crashes randomly on startup dotnet/macios#21485
2. error XARLP7000: Xamarin.Tools.Zip.ZipException: Renaming temporary file failed: No such file or directory dotnet/android#9321
3. Specifying both -f ... and -r ... to dotnet build fails to restore if multiple frameworks are present in the project file dotnet/sdk#21877 (macos)
4. iOS app startup slow in debug dotnet/macios#22310
5. iOS Hot Restart does not work for non-MAUI apps
6. clang error compiling for iOS microsoftgraph/msgraph-sdk-dotnet#2617

VS Code / C# DevKit

1. [NETSDKE2E] TextDocument error occurred after creating component from tag by light bulb. dotnet/vscode-csharp#8480

WebAssembly

1. [mono][interp] NIY assertion crash in WASM Hybrid AOT when GC finalizes native callback delegate dotnet/runtime#121959
2. [API Proposal]: WASM DotnetHostBuilder assembly loading progress callback dotnet/runtime#93941 (comment)
3. [browser] WasmAppHost should not force COOP/COEP when not using threading dotnet/runtime#109937
4. [Wasm][post-MVP] Memory64 support  dotnet/runtime#94108

Roslyn issues

1. HR fails when requesting an intermediate empty update dotnet/roslyn#79898
2. HR fails when removing a property with an initializer from a partial class dotnet/roslyn#79320
3. [EnC] Unexpected null - file EditSession.cs when updating the body of a method in a nested class when marked with CreateNewOnMetadataUpdate dotnet/roslyn#76989
4. CLaSP and Language Server Public API dotnet/roslyn#68696

WinUI / WinAppSDK

1. MetadataUpdateHandlers are not called when running in packaged mode
2. Simplified inline syntax for RowDefinitions/ColumnDefinitions breaks XAML Hot Reload microsoft/microsoft-ui-xaml#5944
3. Proposal: Non-XAML ThemeResource microsoft/microsoft-ui-xaml#10029
4. Crash when using PublishTrimmed with Packaged app and attempting to reference IValueConverters from external library microsoft/microsoft-ui-xaml#9021
5. MenuFlyout DropShadow persists after it is dismissed microsoft/microsoft-ui-xaml#9485
6. Trying to use a FileOpenPicker while running the app as Administrator will crash the app microsoft/WindowsAppSDK#2504
7. Critical crash in WinUI with attached properties in style. microsoft/microsoft-ui-xaml#6388
8. NumberBox Description does not wrap microsoft/microsoft-ui-xaml#8998
9. NavigationBackButtonNormalStyle is wrong when used directly microsoft/microsoft-ui-xaml#9536
10. TreeView crashes when using TemplateSelector and loading certain amount of nodes microsoft/microsoft-ui-xaml#8791
11. ListView items stop responding as Drag and Drop targets microsoft/microsoft-ui-xaml#9043
12. [Run Text] No Text DependencyProperty available to be able to bind a value in code behind microsoft/microsoft-ui-xaml#8253
13. Random coreclr.dll Access Violations microsoft/microsoft-ui-xaml#10660
14. Ctrl+V accelerator and TextBox paste event not working when replacing TextBox ContextFlyout with custom menu with accelerators microsoft/microsoft-ui-xaml#9068
15. WinUI 3 Cant instantiate a UserControl from a location outside the application package or directory (XamlParseException) microsoft/microsoft-ui-xaml#6299
16. Back navigation button styles seem to be reversed microsoft/microsoft-ui-xaml#8636
17. Proposal: Bring C# 9 "Init-Only" properties to XAML microsoft/microsoft-ui-xaml#2519
18. ToggleSwitch control internally sets a MinWidth to 154, which is way larger than its default width microsoft/microsoft-ui-xaml#3652
19. Proposal: enable styling SVGs in Xaml microsoft/microsoft-ui-xaml#507
20. Proposal: Update the Figma design toolkit to modern figma standards and new UI Kit support microsoft/microsoft-ui-xaml#9774
21. Nested ItemsView Items stays highlighted on PointerOver microsoft/microsoft-ui-xaml#10314
22. Can't specify x:DataType of DataTemplate in ResourceDictionary microsoft/microsoft-ui-xaml#10571

Windows Community Toolkit

1. AdvancedCollectionView ArgumentOutOfRangeException when remove the last element CommunityToolkit/WindowsCommunityToolkit#4263
2. TypeLoadException in Release using Behaviors with an ICommand CommunityToolkit/WindowsCommunityToolkit#4022
3. Show compatible targets within docs and gallery CommunityToolkit/Tooling-Windows-Submodule#144

.NET

• EnableWindowsTargeting is broken in .NET 10 Preview 4 (Microsoft.WindowsDesktop.App.Ref not found) dotnet/sdk#48949
• [browser][publish] Windows has problems with AOT build/publish for long paths dotnet/runtime#103625
• Add design for simplifying workload versioning dotnet/designs#294

DocFx

1. [Feature Request] xref link doesn't work as an include link dotnet/docfx#8712

Active for NuGet

• Support SDK Version Management NuGet/Home#13127
• [source mapping] Having a duplicate source breaks msbuild sdks restore NuGet/Home#13471

Active for Xamarin.UITest

Active for Roslyn (Source Generation)

Resolved (Pending Release)

1. Unknown VSIX warning
2. Class Vector3 field assignation overwrites the next field's contents when using LLVM AOT dotnet/runtime#110820
3. WSL HotReload does not invoke MetadataUpdater properly | [Uno] MetadataUpdateHandler is not executed when applying C# hot reload
4. Metadata handlers are not executed
5. [Wasm] Support for the mono log profiler for memory profiling dotnet/runtime#107312
6. WSL launch profile cannot be found when net8.0 is not the first target framework if net8.0-ios/android/maccatalyst are present
7. [wasm] problem with native linking against skiasharp and emscripten 3.1.56 dotnet/runtime#109289

Resolved (Released)

1. Office debugging
2. Hot restart popup keeps appearing
3. WinAppSDK Unpackaged profile cannot be selected properly when a net8.0 mobile target is active (Selecting 'WinAppSdk Unpackaged' from the targets dropdown automatically defaults to 'WinAppSdk Packaged' #19410)
4. appxmanifest failure
5. Support "Supplied by Platform" scenario in restore NuGet/Home#7344
6. NuGet Restore restoring old versions of transitive dependencies when direct dependency does not have guidelines for user's targeted .NET Framework NuGet/Home#13934
7. Managed vtable types (ie. containing any reference types) are not supported. (With WindowsSdkPackageVersion 10.0.19041.38) mono/SkiaSharp#2999
8. [Wasm][AOT] methods with try/catch/finally blocks are not AOTed dotnet/runtime#111281
9. EnC workspace does not report on generators diagnostics dotnet/roslyn#70863
10. Partner Center reporting a bug for latest version of BuildTools microsoft/WindowsAppSDK#4480 [Workarounds to undo - see PRs mentioned in https://github.com/Update Microsoft.Windows.SDK.BuildTools #18840]

• Projects not loading using pre-release extensions microsoft/vscode-dotnettools#1391 and [VS Code] Stuck loading projects #18139

1. [iOS] Cannot set breakpoint on the specified IL offset. dotnet/macios#21758
2. WebAssembly debugging is freezing the IDE
3. net8.0 must be first for WSL debugging to work
4. net8.0-windows10 needs to be first for WinAppSDK Hot reload to work
5. package.appxmanifest cannot be opened
6. Runtime crash with Hot Reload in libmono-component-debugger.so dotnet/runtime#105774
7. Missing androidx.window.[extensions|sidecar] warnings dotnet/android#6809
8. https://developercommunity.visualstudio.com/t/x:DataType-is-not-recognized-on-DataTemp/10617352
9. Solution loading hangs in 17.11
10. Provide full updateTypes to MetadataUpdateHandlers dotnet/aspnetcore#52937
11. ReflectionXamlMetadataProvider GetXamlType taking more than 17 seconds to execute at app startup microsoft/microsoft-ui-xaml#1521
12. App freezes with ItemsPresenter + UniformGridLayout + Binding in ItemTemplate microsoft/microsoft-ui-xaml#6689
13. dotnet build fails when WindowsAppSDK is referenced in console application.  microsoft/WindowsAppSDK#3548
14. TreeView doesn't preserve the value of IsExpanded when containers in "content mode" are recycled and reused microsoft/microsoft-ui-xaml#9549
15. Build conflicts caused by standalone WebView2 and embedded WebView2 (in Windows App SDK) microsoft/WindowsAppSDK#4249 (Related Uno.WinUI.MSAL and WindowsAppSDKSelfContained clash #14555)

• Building with net8.0-ios is picking net8.0 from NuGet package instead of net8.0-ios17.0 NuGet/Home#13510

7. Build action for Content cannot be changed
8. Add usings refactoring fails after a few tries
9. [net7] Creating a cross-targeted net7.0-ios + net6.0-ios packages forces consumers to build with net7 workloads dotnet/sdk#30103
10. ICU causes crash on iOS 17.4 simulator dotnet/runtime#98941
11. [Build performance of SDK style projects for specific target frameworks in Libraries](https://developercommunity.visualstudio.com/t/Building-a-cross-targeted-project-with-m/651372?space=8&q=building-a-
    cross-targeted-project-with-many-target)
12. version conflict WindowsAppSDK 1.3 unpackaged microsoft/WindowsAppSDK#3591

• dotnet --getProperty can sometime return more than one value dotnet/sdk#38944

1. Syntax classification taking up to 12% of CPU time dotnet/roslyn#68996
2. Popup Overlay Incorrect in Scale/Transform Scenarios -- Regression after 1.3.230724000 microsoft/microsoft-ui-xaml#9433
3. Unable to scroll content of new ScrollViewers after closing a window. Issue not present in 1.5 Experimental 1 and earlier microsoft/microsoft-ui-xaml#9355
4. XAML Intellisense does not recognize types when no WinUI project is present (Uno:
   Intellisense in VS2022 not working when the Windows head is not included #15517)
5. Application Hangs When DPI Aware and Desktop Scaling at 150% microsoft/microsoft-ui-xaml#9327
6. Duplicate assets when referencing a chain of nuget packages microsoft/microsoft-ui-xaml#8857
7. [monovm] Assertion at object.c:657, condition `lock->done' not met dotnet/runtime#96872
8. Rollback file based workload update fails to upgrade from 8.0.100 to 8.0.101 dotnet/sdk#37958
9. [Hot Reload] metadata.c:1326, condition `GINT_TO_UINT32(idx) < table_info_get_rows (t)' not met dotnet/runtime#93860
10. iOS App is getting killed by Watchdog on physical device when debugging #10748
11. Building a NET6/NET7 iOS project on agent M2 ARM 64 hangs/freezes dotnet/msbuild#8970
12. [net6][Catalyst] Testflight published app fails to start with security policy does not allow @ path expansion dotnet/macios#14686
13. 3.1% allocations of TypeConversions dotnet/roslyn#68997
14. Can't debug Android or iOS Application and Deploying fails with null reference exception dotnet/android#8199

• [workloads] dotnet verify fails on 7.0.401 on some Windows machines dotnet/sdk#36270
• [Hot Reload] ENC0003: Updating 'attribute' requires restarting the application caused by AssemblyInformationalVersionAttribute dotnet/sdk#36666

1. PM UI multi targeting experience is incomplete - support for updating and uninstalling conditional package versions NuGet/Home#4681 (NuGet Package manager does not honor conditional nuget package references)
2. Blazor Wasm Hot Reload fails because of broken browser link connection
3. iOS Debugger Indicates App Has Terminated Immediately dotnet/maui#9056
4. XAML Intellisense is not working
5. [net6] Poor performance for macOS running on CoreCLR dotnet/macios#15145 (macos)
6. Building a NET6/NET7 iOS project on agent M2 ARM 64 hangs/freezes dotnet/msbuild#8970
7. [net8 preview 2] dotnet new command never finishes for unknown parameter condition evaluation dotnet/templating#6366
8. Breakpoints not working properly in VS 17.61. [Static and Theme resources are not available in XAML intellisense](https://developercommunity.visualstudio.com/t/static-and-theme-resources-are-not-available-in-th/1358108) (Fixed in 17.4 Preview 1)
9. Legacy style projects are not present in the XAML project selector Fixed in fix(msix): Adjust project creation ordering #5161
10. UWP Intellisense fails when using shared projects (Fixed in 16.9 Preview 3)
11. XAML Editor window may be empty (Fixed in 16.9 Preview 3)
12. [Wasm][AOT] Profiled AOT compilation fails with Segmentation fault dotnet/runtime#70773
13. [Wasm][Threading] garray.c:226: assertion 'array != NULL' failed dotnet/runtime#70572
14. [Wasm][Threading] Task.Delay only continues after a GC dotnet/runtime#70571
15. 1. [EnC] Upgrade change types for containing types dotnet/roslyn#68368
16. No compatible code running on the thread #12635 https://developercommunity.visualstudio.com/t/no-compatible-code-running-on-the-thread/103767231. https://developercommunity.visualstudio.com/t/Dotnet-template-not-being-correctly-exec/10413001

• [Xamarin.Android] Assertion tramp-arm64.c:52, condition '((ins >> 24) & 0x1f) == 0x10' not met dotnet/android#7352

1. "Missing value for TargetPlatformWinMDLocation property" when adding a project reference (Not relevant anymore with net6.0+ projects)
2. "Ensure Event Failed" when generating event handler with "New Event Handler" option (Not relevant anymore with net6.0+ projects)
3. Invalid MSBuild properties for Shared projects (Still present in 17.3 Preview 2)
4. ContentPropertyAttribute support for custom assemblies see also XAML Intellisense for inner elements #1407
5. vs4mac globbing issue with the Uno solution
6. XAML Hot Reload in shared projects does not work (Fixed in 16.8)
7. Initial Xaml Intellisense behavior
   Resolved (via Guidance)
8. Code editor project selector switches back to the previous project when clicking the editor

• VS16.x Killer hangs/UI freezes (Released in VS16.2 Pre 4)
• Compilation errors with Microsoft Visual Studio Enterprise 2019 Preview - Version 16.2.0 Preview 4.0

1. Regression - Invalid file name: It must contain only ^a-zA-Z0-9_.+. moved to Re-enable AAPT2 in the Samples and the Uno Solution Template #1382
2. Este proyecto hace referencia a los paquetes NuGet que faltan en este equipo. Use la restauración de paquetes NuGet para descargarlos
3. Android:
   App does not contain a definition for 'InitializeComponent' and no accessible extension method 'InitializeComponent'
4. Shared projects globbing support
5. WebAssembly TFM support (see also VS Dev Community) (not needed as of Uno 3.x)
6. XAML Intellisense is disabled for sdk-style projects (VS 16.9 Pre 3 and later) Worked around in Uno 4.3 as a results of MAUI/WinAppSDK new features ported to Uno.

• Xamarin.iOS fails when running in the simulator with VS4Mac 8.2

• WebAssembly HttpClient fails under AOT (Fixed in mono master)