I was using XLS padlock Version 2.2.1 in 2015/2016, but it didi not work because of different errors which could not be sovled. Thus I gave up. Now I have a new project and tried it again the Version 2.2.1. Unfortunately there was the permanent Error message that EXCEL cannot save, because the file ist locked by a different user to be processed. Finally I tried the newest version 2018.1 successfully. The error was solved. Therefore I need an upgrade. Do I have to pay the full prize or is there an upgrade available?