7.0.md

title	titleSuffix	description	ms.date	no-loc
Breaking changes in .NET 7		Navigate to the breaking changes in .NET 7.	07/28/2023	Blazor Razor Kestrel

Breaking changes in .NET 7

If you're migrating an app to .NET 7, the breaking changes listed here might affect you. Changes are grouped by technology area, such as ASP.NET Core or Windows Forms.

[!INCLUDE binary-source-compat]

ASP.NET Core

Title	Binary compatible	Source compatible
API controller actions try to infer parameters from DI	✔️	❌
ASPNET-prefixed environment variable precedence	✔️	✔️
AuthenticateAsync for remote auth providers	✔️	❌
Authentication in WebAssembly apps	❌	✔️
Default authentication scheme	❌	✔️
Event IDs for some Microsoft.AspNetCore.Mvc.Core log messages changed	❌	✔️
Fallback file endpoints	❌	✔️
IHubClients and IHubCallerClients hide members	✔️	❌
Kestrel: Default HTTPS binding removed	❌	✔️
Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv and libuv.dll removed	❌	❌
Microsoft.Data.SqlClient updated to 4.0.1	✔️	❌
Middleware no longer defers to endpoint with null request delegate	❌	✔️
MVC's detection of an empty body in model binding changed	❌	✔️
Output caching API changes	❌	❌
SignalR Hub methods try to resolve parameters from DI	✔️	❌

Core .NET libraries

Title	Binary compatible	Source compatible
API obsoletions with default diagnostic ID	✔️	❌
API obsoletions with non-default diagnostic IDs	✔️	❌
BinaryFormatter serialization APIs produce compiler errors	✔️	❌
BrotliStream no longer allows undefined CompressionLevel values	❌	✔️
C++/CLI projects in Visual Studio	✔️	❌
Changes to reflection invoke API exceptions	❌	✔️
Collectible Assembly in non-collectible AssemblyLoadContext	❌	✔️
DateTime addition methods precision change	✔️	✔️
Equals method behavior change for NaN	❌	✔️
EventSource callback behavior	✔️	✔️
Generic type constraint on PatternContext<T>	❌	❌
Legacy FileStream strategy removed	❌	✔️
Library support for older frameworks	❌	❌
Maximum precision for numeric format strings	❌	✔️
SerializationFormat.Binary is obsolete	❌	❌
System.Drawing.Common config switch removed	✔️	✔️
System.Runtime.CompilerServices.Unsafe NuGet package	✔️	✔️
Time fields on symbolic links	❌	✔️
Tracking linked cache entries	❌	✔️
Validate CompressionLevel for BrotliStream	❌	✔️

Configuration

Title	Binary compatible	Source compatible
System.diagnostics entry in app.config	❌	✔️

Cryptography

Title	Binary compatible	Source compatible
Decrypting EnvelopedCms doesn't double unwrap	❌	✔️
Dynamic X509ChainPolicy verification time	❌	✔️
X500DistinguishedName parsing of friendly names	❌	✔️

Deployment

Title	Binary compatible	Source compatible
All assemblies trimmed by default	✔️	❌
Multi-level lookup is disabled	❌	✔️
x86 host path on 64-bit Windows	✔️	✔️
TrimmerDefaultAction is deprecated	✔️	❌

Entity Framework Core

Breaking changes in EF Core 7

Extensions

Title	Binary compatible	Source compatible
ContentRootPath for apps launched by Windows Shell	❌	✔️
Environment variable prefixes	❌	✔️

Globalization

Title	Binary compatible	Source compatible
Globalization APIs use ICU libraries on Windows Server	❌	✔️

Interop

Title	Binary compatible	Source compatible
RuntimeInformation.OSArchitecture under emulation	❌	✔️

.NET MAUI

Title	Binary compatible	Source compatible
Constructors accept base interface instead of concrete type	❌	✔️
Flow direction helper methods removed	❌	❌
New UpdateBackground parameter	❌	✔️
ScrollToRequest property renamed	❌	❌
Some Windows APIs are removed	❌	❌

Networking

Title	Binary compatible	Source compatible
AllowRenegotiation default is false	❌	❌
Custom ping payloads on Linux	❌	✔️
Socket.End methods don't throw ObjectDisposedException	❌	✔️

SDK and MSBuild

Title	Binary compatible	Source compatible
Automatic RuntimeIdentifier for certain projects	✔️	❌
Automatic RuntimeIdentifier for publish only	❌	❌
CLI console output uses UTF-8	❌	❌
Console encoding not UTF-8 after completion	❌	✔️
MSBuild serialization of custom types in .NET 7	❌	❌
Side-by-side SDK installations	❌	❌
Tool manifests in root folder	✔️	✔️
Version requirements for .NET 7 SDK	✔️	✔️
dotnet test: switch -a to alias --arch instead of --test-adapter-path	❌	❌
dotnet test: switch -r to alias --runtime instead of --results-dir	❌	❌
--output option no longer is valid for solution-level commands	❌	❌
SDK no longer calls ResolvePackageDependencies	✔️	❌

Serialization

Title	Binary compatible	Source compatible
DataContractSerializer retains sign when deserializing -0	❌	✔️
Deserialize Version type with leading or trailing whitespace	❌	✔️
JsonSerializerOptions copy constructor includes JsonSerializerContext	❌	✔️
Polymorphic serialization for object types	❌	✔️
System.Text.Json source generator fallback	❌	✔️

Windows Forms

Title	Binary compatible	Source compatible
Obsoletions and warnings	✔️	❌
Some APIs throw ArgumentNullException	❌	✔️

XML and XSLT

Title	Binary compatible	Source compatible
XmlSecureResolver is obsolete	❌	❌

See also

• What's new in .NET 7