Worked on the flutter/flutter repository to enhance the stability of the web-server platform toggling process. Addressed a critical issue where the absence of a vmService instance could cause crashes during device or platform switching, particularly when running flutter commands targeting web-server devices. Introduced a null guard in the Dart codebase, ensuring the tool exits gracefully with an informative message rather than failing unexpectedly. Supplemented this fix with targeted tests to verify correct handling of null vmService scenarios, maintaining future code safety. All changes adhered to Flutter contribution guidelines, with comprehensive documentation and passing tests, utilizing Dart, Flutter, and testing skills.