Overview
Modern data recovery software (including the current EasyRecovery by KLDiscovery) uses annual subscriptions. A single license can cost $200–$500 per year. Version 6.03 was a perpetual license—pay once, own forever. Users want the "full" unlocked version to avoid recurring fees.
The "Professional" edition of version 6.03 offered a more advanced feature set compared to the standard Home version, specifically tailored for business environments and advanced users.
If you are trying to recover data on a modern computer, you will have much higher success rates with current software that understands modern TRIM commands (for SSDs) and advanced encryption.