Paradex, an on-chain derivatives platform, has refunded approximately $650,000 to around 200 users following a maintenance-related software bug that led to unintended liquidations. The issue arose during a planned 30-minute database upgrade, which resulted in corrupted market data being written on-chain. Paradex responded by pausing access, canceling most open orders, and rolling back the chain to a pre-maintenance snapshot to protect users. The company emphasized that the incident was operational, not a hack, and has since implemented several procedural and risk-control enhancements. These include updated restart procedures, stronger data validation, revised maintenance scaling, and price-band protections for post-only trading periods. Paradex's actions highlight the importance of robust incident response and data integrity controls in on-chain trading systems.