ASP.NET Core Stops Turning 413 Into 500 in UseExceptionHandler
A PR merged into dotnet/aspnetcore main on August 19, 2026 makes ExceptionHandlerMiddleware honour BadHttpRequestException.StatusCode instead of overwriting it with 500.
Tag: dotnet-11
313 posts · Page 7 of 32
Fix: [FromForm] Dictionary<string, string> is always null in a minimal API
A [FromForm] Dictionary in a minimal API binds with an empty prefix: the form keys must be [key], not metadata[key]. Wrap it in a class to keep readable names.
Fix: cannot target OpenAPI 3.0 after upgrading Swashbuckle.AspNetCore to v9
Swashbuckle 8 and later emit openapi 3.0.4, not 3.0.1, and there is no OpenApiSpecVersion for a patch version. Why it changed, and four ways to pin the string your tooling expects.
Fix: Swagger UI shows Unable to render this definition after upgrading to .NET 11
ASP.NET Core 11 emits openapi 3.2.0 by default and Swagger UI below 10.1.5 rejects it. Upgrade Swashbuckle.AspNetCore.SwaggerUI, or pin OpenApiVersion back to OpenApi3_1.
MSBuild Server Is On by Default in .NET 11 Preview 7
Preview 7 flips MSBuild server from opt-in to on by default, so back-to-back dotnet build and dotnet test calls reuse a warm worker process. Here is what changed, how to opt out, and how to prove the server actually engaged.
How to generate a primary key from a database sequence on insert in EF Core 11
Move a key off IDENTITY and onto a SQL Server sequence in EF Core 11 with UseSequence: the exact SQL EF emits, why explicit key values suddenly work without IDENTITY_INSERT, the bigint sequence feeding an int column, and the gaps you have to design around.
How to download a file from a Blazor component without JavaScript interop
Skip the downloadFileFromStream JS module entirely. Render an anchor with the download attribute pointing at a minimal API endpoint that returns TypedResults.File, or POST a plain HTML form with an AntiforgeryToken. Covers why the download attribute is what stops Blazor's enhanced navigation from swallowing the click, why data-enhance silently discards the file, and the cookie-vs-bearer auth trap.
How to use IDbContextFactory<T> from a singleton service in Blazor
A singleton cannot inject a DbContext, but it can inject IDbContextFactory<T>, because AddDbContextFactory registers the factory as a singleton by default. Create and dispose one context per call, never cache the instance.
System.IO.Compression Finally Reads and Writes Encrypted ZIPs in .NET 11 Preview 7
.NET 11 Preview 7 adds password-protected ZIP entries to System.IO.Compression, with AES-256 support, options types for whole-directory operations, and one empty-file bug that is already fixed in main.
Scalar vs Swagger UI for OpenAPI documentation in ASP.NET Core 11
Scalar ships 1.02 MiB of gzipped JavaScript and a far better request builder. Swagger UI ships 514 KiB and renders OpenAPI 3.2, which is what .NET 11 now emits by default. Measured payloads, the 3.2 gap, endpoint routing on both sides, and the auth details that decide it.