Yes, the software is listed as free. I have also downloaded the available version and installed it on Windows 10 64bit and it worked normally. There were no nag screens or pop ups to ask me about registration data. The error you receive is directly related to the lack of Net Framework installation in your computer because ClassNotRegistered belongs to Net Frameworks.
Download the package here: http://lededit-2013.software.informer.com/download/
Note: Wait a little and the download will start automatically.
Install guide: Extract the archive with your favorite archiver and install the program in the dotnetfx folder. After this procedure, restart the PC and launch the software again.
