Contact your local Siemens distributor with the part number 6ES7810-4CC11-0YA5 and ask for a "Step7 Professional V5.5 Floating License." Or, if you have an active Siemens support contract, request the legacy software from the Industry Online Support download area. That is the only way to get a real, working license key.
Introduction: The Backbone of Classic PLC Programming For over two decades, Siemens SIMATIC Step7 has been the gold standard for programming Programmable Logic Controllers (PLCs) in industrial automation. Specifically, Version 5.5 (often referred to as V5.5) represents a critical milestone—the last major release of the classic Step7 interface before Siemens shifted focus to the TIA Portal (Totally Integrated Automation Portal) with Step7 Professional. siemens simatic step7 v5 5 profesional license key