altera_up_avalon_character_buffer.h: No such file or directory Nios II IDE error

When I try to compile the "Pixel Buffer core C Example using Device Drivers" from the pdf called Video IP Cores for Altera DE-Series Boards page 36, I get an error ->altera_up_avalon_character_buffer.h: No such file or directory. I attached the PDF. Does anyone know how to fix the error for the header file.