Fix: CS1998 "This async method lacks 'await' operators and will run synchronously" in C#
CS1998 means an async method has no await, so it runs synchronously. Drop the async modifier and return Task.FromResult, or add the await you forgot.
Tag: csharp-14
20 posts · Page 1 of 2
Fix: CS4014 "Because this call is not awaited, execution of the current method continues" in C#
CS4014 means you called a Task-returning method without awaiting it. Add await, or discard with _ = if fire-and-forget is truly intended, and handle exceptions.
Fix: CS8618 "Non-nullable property must contain a non-null value when exiting constructor" in C#
CS8618 means a non-nullable field or property was not initialized by the time the constructor finished. Set it in the constructor, give it a default, mark it required, or make it nullable.
Fix: CS9035 "Required member 'X' must be set in the object initializer" in C#
CS9035 means a member marked required was not assigned. Set it in the object initializer, or add a constructor annotated with [SetsRequiredMembers] that assigns every required member.
How to declare extension properties in C# 14
Extension properties land in C# 14 through the new extension block. Declare get-only, settable, static, and generic extension properties, why auto-properties are rejected, and how the compiler lowers them to get_/set_ accessors.
Migrate from .NET 8 to .NET 11: the full checklist
A version-pinned migration checklist from .NET 8 LTS to .NET 11 LTS, covering SDK install, csproj target framework, breaking changes in ASP.NET Core, EF Core, System.Text.Json, and the C# 14 overload-resolution shift, with rollback notes.
Fix: C# 14 overload resolution breaking change with Span and ReadOnlySpan
After upgrading to C# 14 / .NET 10, calls like array.Contains, x.Reverse(), and MemoryMarshal.Cast suddenly bind to different overloads or stop compiling. Here is what changed and how to pin the old behaviour where it matters.
How to Build a Custom MCP Server in C# on .NET 11
Build a working Model Context Protocol server in C# 14 / .NET 11 using the official ModelContextProtocol 1.2 SDK. Covers stdio transport, [McpServerTool] attributes, dependency injection, the stderr logging trap, and registration with Claude Code, Claude Desktop, and VS Code.
How to read a large CSV in .NET 11 without running out of memory
Stream a multi-gigabyte CSV in .NET 11 without OutOfMemoryException. File.ReadLines, CsvHelper, Sylvan, and Pipelines compared with code and measurements.
How to return multiple values from a method in C# 14
Seven ways to return more than one value from a C# 14 method: named tuples, out parameters, records, structs, deconstruction, and the extension-member trick for types you don't own. Real benchmarks and a decision matrix at the end.