@User uploaded a file: and commented: one more issue is when referring an inner class constructor, it says Unresolved ref error. https://github.com/jnr/jnr-ffi/blob/master/src/main/java/jnr/ffi/StructLayout.java#L1573 https://github.com/jnr/jnr-ffi/blob/master/src/main/java/jnr/ffi/StructLayout.java#L695