Plugins will be installed into program folder which you may not have write permissions to.

The shell (or CMD.EXE) cannot find the make or some other compiler specific programs. Make sure you have C/C++ compiler installed. The Path environment variable should contain paths to appropriate compiler folders so that compiler specific programs, such as make, can be found. Note for MS Visual C++ users: MSVC creates a bat file vcvars32.bat or vcvarsall.bat, which sets the necessary environment variables for using MSVC from CMD window. If you have installed MSVC, you should find this file somewhere from your hard drive.

SDK was installed on a folder which contains white spaces. This problem only shows up on Windows platforms. Make sure the setup folder for the SDK does not contain white spaces.

If you use C++ (your source file is named .cpp or .cc), make sure you use 'C' calling convention. C++ and C use different function decoration and you must use extern "C" directive to tell your compiler that you call 'C' function rather than C++.

Make sure you link appropriate r3 link libraries.