Worked on stabilizing the Microsoft Graph .NET SDK by addressing a critical bug in the Drive Item Versions API within the microsoftgraph/msgraph-sdk-dotnet repository. Focused on SDK development using C#, the work involved correcting an incorrect type reference in DriveItemRequestBuilderExtensions.cs to resolve a path resolution issue affecting drive item versions. This technical fix improved internal routing accuracy and enhanced type-safety for the API, ensuring more reliable version management within the SDK. The contribution was delivered through a targeted pull request and merged after review, reflecting a methodical approach to maintaining code quality and robustness in a complex SDK environment.