utility/u8g.h error

Hello, i know that there are other topics here that is similar to mine but i'm still unable to solve my issue.
I'm very new to arduino so help is much appreciated!
Basically i'm trying a code i found online for a flow meter sensor found here and also inserted a U8glib.h file downloaded from here.
After verifying my code, it is mentioned that there was an error compiling my code.

fatal error: utility/u8g.h: No such file or directory
#include "utility/u8g.h"

How do i solve this problem? Thanks!

Where did you put the files is the main question? Libraries should go in the libraries folder inside you sketchbook (\documents\Arduino). Easiest way, delete the u8g files you have now and download u8g library from the library manager.