Welcome to the source code of the CSurf_Klinke_MCU Extension for Reaper (v3.6 or higher). This extension enhances support for the Mackie Control Universal (MCU) controller, but can also be used for other controllers that use the MCU protocol (please read the manual of your controller to check if and how your controller supports this protocol). Beside the Reaper SDK the code also depends on the JUCE and BOOST libraries. So you will need to indicate three SDK locations via environment variables. Sometimes the JUCE library is not backward compatible, therefore you need v1.50 or v1.52! Example: The juce SDK (v1.52) is installed in C:\juce and the header file is found in C:\juce\juce.h Set the environment variable in Start -> MyComputer -> RightClick -> Properties -> Advanced -> Environment Variables -> System Variables section -> New Button Variable Name = JUCE Variable Value = C:\juce Of course your actual paths (Variable Values) may be different, but the Variable Names must exactly agree with the ones above, those Variable Names are the ones referenced in the Visual Studio project. For the reaper extensions SDK repeat as above: Example: C:\reaper_extension_sdk Variable Name = REAPER_EXTENSION_SDK Variable Value = C:\reaper_extension_sdk And for the Boost Library (v 1.39.0 or above) repeat again as above: Example: C:\boost Variable Name = BOOST Variable Value = C:\boost All parts of the Boost Library are header-only based, so it's not necessary to compile the libs. For JUCE it's a little bit more complicated. It's important that you use JUCE 1.52, you can download it from https://github.com/julianstorer/JUCE/releases . The project file for Visual Studio 2010 doesn't contain the 64bit build, but I have added an updated project file in the JUCE-changes folder. There you can find also a file called juce_Config.h. It's a good idea to replace the files from the JUCE Download with the files from the JUCE-changes folder. Then load the Visual Studio project and compile the libraries.