"I cannot find version 21.0.1 on the portal." Solution: Your maintenance plan may have expired. Contact ETAP support directly. Alternatively, the portal may default to the latest major version (e.g., 22.0). Check the "Archives" or "Patches" tab.
ETAP 21.0.1 is a major update to the Electrical Transient Analyzer Program
Offers a unified platform for power system modeling and analysis, from planning to real-time operations.