Many industries are transitioning to Industry 4.0 production models by adopting robots in their processes. In parallel, Extended Reality (XR) technologies have reached sufficient maturity to enter the industrial applications domain, with early success cases often related to training workers, remote assistance, access to contextual information, and interaction with digital twins. In the future, robots will be increasingly enhanced with XR applications, which requires that industrial workers understand both technologies and can use and control hybrid solutions confidently. According to the data published in 2021, XR will create 1.2-2.4 million new jobs in the EU by 2025, and European XR markets are expected to grow between €35 billion and €65 billion by 2025. Specific education and training programs will be essential to this transition, especially for vocational school students and professionals in upskilling. They must learn how to program robots and establish a safe and productive human-robot collaboration. The new EU-funded project MASTER will improve the XR ecosystem for teaching and training robotics in manufacturing by providing an open XR platform that integrates key functionalities like creating safe robotic environments, programming flexible robotic applications, and integrating advanced interaction mechanisms. It will also provide high-quality training materials for robotics. Third-party contributions in terms of additional technologies and educational content will be integrated through two open calls for participation. Close collaboration with industry partners also serves to validate the open XR platform. The project started in January with a kick-off meeting at the University of Patras.