This can be caused by asking for a library version higher than you need (Do not use the #define LIBRARY_VERSION when compiling!). Can also be caused by calling functions or using structures which do not exist in the older version of the operating system. Ask for the lowest version which provides the functions you need (usually 33), and exit gracefully and informatively if an openlibrary() fails (returns null). or code conditionally to only use new functions and structures if the available Library's lib_version supports them.