Grid layout changed

My grid on my waste board has changed from one inch and 1/8 inch to 0 and then 12 inch. Before I could see from 0 grid to whatever the size by inches and even the 1/8 inch increments. Anyone know what went wrong and how do I fix this. I’m frustrated with this problem. I have tried everthing I could think of and need some help fast! Can’t find the tech support phone number to call them for a correction.

thanks in advance,

larry