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.
This article categorizes each breaking change as binary incompatible or source incompatible:
- Binary incompatible - Existing binaries may encounter a breaking change in behavior, such as failure to load or execute, or different run-time behavior.
- Source incompatible - Source code may encounter a breaking change in behavior when targeting the new runtime or using the new SDK or component. Behavior changes can include compile errors or different run-time behavior.
Note
This article is a work in progress. It's not a complete list of breaking changes in .NET 7. To query breaking changes that are still pending publication, see Issues of .NET.
ASP.NET Core
| Title | Binary compatible | Source compatible | Introduced |
|---|---|---|---|
| API controller actions try to infer parameters from DI | ✔️ | ❌ | Preview 2 |
| Event IDs for some Microsoft.AspNetCore.Mvc.Core log messages changed | ❌ | ✔️ | Preview 3 |
| Microsoft.AspNetCore.Server.Kestrel.Transport.Libuv and libuv.dll removed | ❌ | ❌ | Preview 1 |
| Microsoft.Data.SqlClient updated to 4.0.1 | ✔️ | ❌ | Preview 2 |
| MVC's detection of an empty body in model binding changed | ❌ | ✔️ | Preview 3 |
| SignalR Hub methods try to resolve parameters from DI | ✔️ | ❌ | Preview 2 |
Core .NET libraries
| Title | Binary compatible | Source compatible | Introduced |
|---|---|---|---|
| API obsoletions with non-default diagnostic IDs | ✔️ | ❌ | Preview 1 |
| C++/CLI projects in Visual Studio | |||
| Collectible Assembly in non-collectible AssemblyLoadContext | ❌ | ✔️ | Preview 5 |
| Equals method behavior change for NaN | ❌ | ✔️ | Preview 5 |
| FullPath and OldFullPath return fully qualified path | ✔️ | ❌ | Preview 1 |
| Generic type constraint on PatternContext<T> | ❌ | ❌ | Preview 3 |
| SerializationFormat.Binary is obsolete | ❌ | ❌ | Preview 2 |
| Validate CompressionLevel for BrotliStream | ❌ | ✔️ | Preview 1 |
Cryptography
| Title | Binary compatible | Source compatible | Introduced |
|---|---|---|---|
| Decrypting EnvelopedCms doesn't double unwrap | ❌ | ✔️ | Preview 5 |
| X500DistinguishedName parsing of friendly names | ❌ | ✔️ | Preview 5 |
Deployment
| Title | Binary compatible | Source compatible | Introduced |
|---|---|---|---|
| Multi-level lookup is disabled | ❌ | ✔️ | Preview 4 |
Networking
| Title | Binary compatible | Source compatible | Introduced |
|---|---|---|---|
| AllowRenegotiation default is false | ❌ | ❌ | Preview 3 |
| Custom ping payloads on Linux | ❌ | ✔️ | Preview 2 |
SDK and MSBuild
| Title | Binary compatible | Source compatible | Introduced |
|---|---|---|---|
| Version requirements for .NET 7 SDK | ✔️ | ✔️ | 7.0.100 |
| MSBuild serialization of custom types in .NET 7 | ❌ | ❌ | 7.0.100 |
Serialization
| Title | Binary compatible | Source compatible | Introduced |
|---|---|---|---|
| Deserialize Version type with leading or trailing whitespace | ❌ | ✔️ | Preview 1 |
Windows Forms
| Title | Binary compatible | Source compatible | Introduced |
|---|---|---|---|
| Some APIs throw ArgumentNullException | ❌ | ✔️ | Preview 1 |
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