Breaking changes in ASP.NET Core 11

If you're migrating an app to ASP.NET Core 11, the breaking changes listed here might affect you.

This article categorizes each breaking change as binary incompatible or source incompatible, or as a behavioral change:

• Binary incompatible - When run against the new runtime or component, existing binaries may encounter a breaking change in behavior, such as failure to load or execute, and if so, require recompilation.

• Source incompatible - When recompiled using the new SDK or component or to target the new runtime, existing source code may require source changes to compile successfully.

• Behavioral change - Existing code and binaries may behave differently at runtime. If the new behavior is undesirable, existing code would need to be updated and recompiled.

Title	Type of change
Blazor custom event registration throws when name matches a browser event	Behavioral change
Blazor enhanced navigation no longer preloads resources	Behavioral change
ConcurrencyLimiter middleware removed	Binary/source incompatible
Hosting emits OpenTelemetry HTTP semantic-convention tags by default	Behavioral change
Kestrel tightens HTTP protocol compliance	Behavioral change
Microsoft.OpenApi upgraded to 3.x	Source incompatible
Obsolete Blazor APIs removed	Source incompatible
OpenAPI document includes all ProducesResponseType entries per status code	Behavioral change
OpenAPI server URL no longer has a trailing slash when PathBase is empty	Behavioral change
Passkey sign-in enforces email/phone confirmation and lockout	Behavioral change
Response compression always emits Vary: Accept-Encoding	Behavioral change
SqlClient Active Directory authentication moved to a separate package	Behavioral change
WebAssemblyHostBuilder loads environment variables into IConfiguration	Behavioral change