Migrate Dotnet8 To Dotnet9
by dotnet0608d8924cd3MIT5.5K starsListed Oct 8, 2026Updated Oct 8, 2026Repository updated today
Migrate a .NET 8 project to .NET 9 and resolve all breaking changes. USE FOR: upgrading TargetFramework from net8.0 to net9.0, fixing build errors after updating the .NET 9 SDK, resolving behavioral changes in .NET 9 / C# 13 / ASP.NET Core 9 / EF Core 9, replacing BinaryFormatter (now always throws), resolving SYSLIB0054-SYSLIB0057, adapting to params span overload resolution, fixing C# 13 compiler changes, updating HttpClientFactory for SocketsHttpHandler, and resolving EF Core 9 migration/Cosmos DB changes. DO NOT USE FOR: .NET Framework migrations, upgrading from .NET 7 or earlier, greenfield .NET 9 projects, or cosmetic modernization unrelated to the upgrade.
Only the file list is public. File contents are available once the skill is installed in a workspace.
| Path | Size | Type |
|---|---|---|
| references/aspnet-core-dotnet8to9.md | 2.3 KB | text/markdown |
| references/containers-interop-dotnet8to9.md | 1.9 KB | text/markdown |
| references/core-libraries-dotnet8to9.md | 7 KB | text/markdown |
| references/cryptography-dotnet8to9.md | 2.1 KB | text/markdown |
| references/csharp-compiler-dotnet8to9.md | 3.3 KB | text/markdown |
| references/deployment-runtime-dotnet8to9.md | 2.4 KB | text/markdown |
| references/efcore-dotnet8to9.md | 6.9 KB | text/markdown |
| references/sdk-msbuild-dotnet8to9.md | 2.3 KB | text/markdown |
| references/serialization-networking-dotnet8to9.md | 5.4 KB | text/markdown |
| references/winforms-wpf-dotnet8to9.md | 3.7 KB | text/markdown |
| SKILL.md | 15.4 KB | text/markdown |
Source and attribution
Source:dotnet/skillsinplugins/dotnet-upgrade/skills/migrate-dotnet8-to-dotnet9at commit0608d89
License: MIT
Content belongs to its original authors. SourceWeft indexes it from a public repository.
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