Worked on stabilizing Monte Carlo data handling in the AliceO2Group/O2Physics repository, focusing on preventing crashes caused by missing McCollision data during simulation workflows. Addressed a critical bug by introducing defensive programming techniques in C++, verifying the existence of mcCollision before accessing its global index in sigmaminustask.cxx. Refactored the MC processing function signature to improve input validation and reduce the crash surface in scenarios with incomplete collision information. This targeted fix enhanced the reliability and maintainability of MC data pipelines, resulting in fewer runtime interruptions and more robust data analysis and physics simulation processes within the O2Physics environment.