System.runtime.compilerservices.unsafe Version 4.0.4.1 Download -

Stay safe, and keep your dependencies clean.

You should never manually download a .dll for this package from a random website. Instead, let NuGet handle it.

The short answer is: But let’s break down what this package is, why version 4.0.4.1 exists, and how to handle it safely in 2025. Stay safe, and keep your dependencies clean

If a project requires 4.0.4.1, NuGet will fetch it from nuget.org automatically when you run:

Without this package, features like System.Memory and modern JSON serialization would be much slower. The short answer is: But let’s break down

Install-Package System.Runtime.CompilerServices.Unsafe -Version 4.0.4.1

If you control the project, run:

If you absolutely need version 4.0.4.1, get it via NuGet. For anything else, use the latest stable version (8.0.0 as of this writing) or rely on the version that comes with your .NET SDK (for .NET Core 3.1+ and .NET 5+, it’s often included implicitly).

dotnet restore or

These files are often trojans, outdated, or unsigned. Always use the official NuGet feed.