My synthesis can't find .lmf file?

I'm using Quartus v18.1 and when I compile my synthesis keeps failing because it can't find the .lmf file in my build? Can somebody from Support help me please resolve this problem? What do I need to do? Do I need to re-install Quartus again? I'm using Device MAX 10? Can somebody really really help?? I've been trying to figure out what to do? This is wasting my time??????????