Worked on stabilizing the Preferences workflow in the mixxxdj/mixxx repository by addressing a critical issue related to sound hardware configuration. Focused on ensuring that the Preferences dialog could not be closed if the sound hardware configuration was invalid, thereby preventing users from applying faulty settings and reducing the risk of disruptive behavior. Implemented a robust validation mechanism using C++ and Qt, which checked the validity of all relevant configuration pages before allowing changes to be saved. This targeted bug fix improved the reliability of the software’s configuration process and contributed to a more predictable and user-friendly experience for end users.