Building is broken in 7.21360.1 and later builds.

[L00pZBreak3r]

The feature 'global using directive' is currently in Preview and unsupported. To use Preview features, use the 'preview' language version.

[marcpopMSFT]

@L00pZBreak3r are you hitting this within VS using that build and what version of VS? Can you provide an https://aka.ms/binlog? @JunTaoLuo for visibility since you just enabled implicit usings in the SDK so this is likely directly related to that.

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[JunTaoLuo]

Can you share you project file? I'm curious what combination of the SDKs and TFMs is causing this.

FYI, there are more details on how to resolve issues in dotnet/docs#25066.

[L00pZBreak3r]

Adding <DisableImplicitNamespaceImports_DotNet> to the project files saved the day.