patch:

0. Remove Corona_43_c4d_fix.dll or any other previous crack

1. Download and install Corona from http://corona-renderer.com/download

2. Copy Corona_52_c4d_fix.dll to the C4D root dir ( C:\Program Files\MAXON\Cinema 4D R21 )
Copy LegionLib_Release.dll to the plugins\corona dir ( C:\Program Files\MAXON\Cinema 4D R21\plugins\corona )
and to the dirs of each other C4D version with the Corona installed, if any

Copy both Corona_52_c4d_fix.dll and LegionLib_Release.dll to the:
Corona Standalone dir ( C:\Program Files\Corona\Corona Renderer for Cinema 4D\Standalone ), if needed
Image Editor dir ( C:\Program Files\Corona\Corona Renderer for Cinema 4D\Image Editor ), if needed

3. Enjoy!

Uninstallation note:

If you want to go legal, then delete Corona_52_c4d_fix.dll and restore the original LegionLib_Release.dll
and REMOVE token-c4d-commercial.txt from the %LOCALAPPDATA%\CoronaRenderer before running and activating Corona
or just execute Delete_token-c4d.bat (also repeat this for every User profile that uses Corona)